Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1 | /* |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 2 | * Performance events core code: |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3 | * |
| 4 | * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> |
| 5 | * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar |
| 6 | * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> |
| 7 | * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
| 8 | * |
Ingo Molnar | 57c0c15 | 2009-09-21 12:20:38 +0200 | [diff] [blame] | 9 | * For licensing details see kernel-base/COPYING |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include <linux/fs.h> |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/cpu.h> |
| 15 | #include <linux/smp.h> |
| 16 | #include <linux/file.h> |
| 17 | #include <linux/poll.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 18 | #include <linux/slab.h> |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 19 | #include <linux/hash.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 20 | #include <linux/sysfs.h> |
| 21 | #include <linux/dcache.h> |
| 22 | #include <linux/percpu.h> |
| 23 | #include <linux/ptrace.h> |
| 24 | #include <linux/vmstat.h> |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 25 | #include <linux/vmalloc.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 26 | #include <linux/hardirq.h> |
| 27 | #include <linux/rculist.h> |
| 28 | #include <linux/uaccess.h> |
| 29 | #include <linux/syscalls.h> |
| 30 | #include <linux/anon_inodes.h> |
| 31 | #include <linux/kernel_stat.h> |
| 32 | #include <linux/perf_event.h> |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 33 | #include <linux/ftrace_event.h> |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 34 | #include <linux/hw_breakpoint.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 35 | |
| 36 | #include <asm/irq_regs.h> |
| 37 | |
| 38 | /* |
| 39 | * Each CPU has a list of per CPU events: |
| 40 | */ |
Xiao Guangrong | aa5452d | 2009-12-09 11:28:13 +0800 | [diff] [blame] | 41 | static DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 42 | |
| 43 | int perf_max_events __read_mostly = 1; |
| 44 | static int perf_reserved_percpu __read_mostly; |
| 45 | static int perf_overcommit __read_mostly = 1; |
| 46 | |
| 47 | static atomic_t nr_events __read_mostly; |
| 48 | static atomic_t nr_mmap_events __read_mostly; |
| 49 | static atomic_t nr_comm_events __read_mostly; |
| 50 | static atomic_t nr_task_events __read_mostly; |
| 51 | |
| 52 | /* |
| 53 | * perf event paranoia level: |
| 54 | * -1 - not paranoid at all |
| 55 | * 0 - disallow raw tracepoint access for unpriv |
| 56 | * 1 - disallow cpu events for unpriv |
| 57 | * 2 - disallow kernel profiling for unpriv |
| 58 | */ |
| 59 | int sysctl_perf_event_paranoid __read_mostly = 1; |
| 60 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 61 | int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */ |
| 62 | |
| 63 | /* |
| 64 | * max perf event sample rate |
| 65 | */ |
| 66 | int sysctl_perf_event_sample_rate __read_mostly = 100000; |
| 67 | |
| 68 | static atomic64_t perf_event_id; |
| 69 | |
| 70 | /* |
| 71 | * Lock for (sysadmin-configurable) event reservations: |
| 72 | */ |
| 73 | static DEFINE_SPINLOCK(perf_resource_lock); |
| 74 | |
| 75 | /* |
| 76 | * Architecture provided APIs - weak aliases: |
| 77 | */ |
| 78 | extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) |
| 79 | { |
| 80 | return NULL; |
| 81 | } |
| 82 | |
| 83 | void __weak hw_perf_disable(void) { barrier(); } |
| 84 | void __weak hw_perf_enable(void) { barrier(); } |
| 85 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 86 | void __weak perf_event_print_debug(void) { } |
| 87 | |
| 88 | static DEFINE_PER_CPU(int, perf_disable_count); |
| 89 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 90 | void perf_disable(void) |
| 91 | { |
Peter Zijlstra | 32975a4 | 2010-03-06 19:49:19 +0100 | [diff] [blame] | 92 | if (!__get_cpu_var(perf_disable_count)++) |
| 93 | hw_perf_disable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 94 | } |
| 95 | |
| 96 | void perf_enable(void) |
| 97 | { |
Peter Zijlstra | 32975a4 | 2010-03-06 19:49:19 +0100 | [diff] [blame] | 98 | if (!--__get_cpu_var(perf_disable_count)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 99 | hw_perf_enable(); |
| 100 | } |
| 101 | |
| 102 | static void get_ctx(struct perf_event_context *ctx) |
| 103 | { |
| 104 | WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); |
| 105 | } |
| 106 | |
| 107 | static void free_ctx(struct rcu_head *head) |
| 108 | { |
| 109 | struct perf_event_context *ctx; |
| 110 | |
| 111 | ctx = container_of(head, struct perf_event_context, rcu_head); |
| 112 | kfree(ctx); |
| 113 | } |
| 114 | |
| 115 | static void put_ctx(struct perf_event_context *ctx) |
| 116 | { |
| 117 | if (atomic_dec_and_test(&ctx->refcount)) { |
| 118 | if (ctx->parent_ctx) |
| 119 | put_ctx(ctx->parent_ctx); |
| 120 | if (ctx->task) |
| 121 | put_task_struct(ctx->task); |
| 122 | call_rcu(&ctx->rcu_head, free_ctx); |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | static void unclone_ctx(struct perf_event_context *ctx) |
| 127 | { |
| 128 | if (ctx->parent_ctx) { |
| 129 | put_ctx(ctx->parent_ctx); |
| 130 | ctx->parent_ctx = NULL; |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | /* |
| 135 | * If we inherit events we want to return the parent event id |
| 136 | * to userspace. |
| 137 | */ |
| 138 | static u64 primary_event_id(struct perf_event *event) |
| 139 | { |
| 140 | u64 id = event->id; |
| 141 | |
| 142 | if (event->parent) |
| 143 | id = event->parent->id; |
| 144 | |
| 145 | return id; |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * Get the perf_event_context for a task and lock it. |
| 150 | * This has to cope with with the fact that until it is locked, |
| 151 | * the context could get moved to another task. |
| 152 | */ |
| 153 | static struct perf_event_context * |
| 154 | perf_lock_task_context(struct task_struct *task, unsigned long *flags) |
| 155 | { |
| 156 | struct perf_event_context *ctx; |
| 157 | |
| 158 | rcu_read_lock(); |
| 159 | retry: |
| 160 | ctx = rcu_dereference(task->perf_event_ctxp); |
| 161 | if (ctx) { |
| 162 | /* |
| 163 | * If this context is a clone of another, it might |
| 164 | * get swapped for another underneath us by |
| 165 | * perf_event_task_sched_out, though the |
| 166 | * rcu_read_lock() protects us from any context |
| 167 | * getting freed. Lock the context and check if it |
| 168 | * got swapped before we could get the lock, and retry |
| 169 | * if so. If we locked the right context, then it |
| 170 | * can't get swapped on us any more. |
| 171 | */ |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 172 | raw_spin_lock_irqsave(&ctx->lock, *flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 173 | if (ctx != rcu_dereference(task->perf_event_ctxp)) { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 174 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 175 | goto retry; |
| 176 | } |
| 177 | |
| 178 | if (!atomic_inc_not_zero(&ctx->refcount)) { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 179 | raw_spin_unlock_irqrestore(&ctx->lock, *flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 180 | ctx = NULL; |
| 181 | } |
| 182 | } |
| 183 | rcu_read_unlock(); |
| 184 | return ctx; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Get the context for a task and increment its pin_count so it |
| 189 | * can't get swapped to another task. This also increments its |
| 190 | * reference count so that the context can't get freed. |
| 191 | */ |
| 192 | static struct perf_event_context *perf_pin_task_context(struct task_struct *task) |
| 193 | { |
| 194 | struct perf_event_context *ctx; |
| 195 | unsigned long flags; |
| 196 | |
| 197 | ctx = perf_lock_task_context(task, &flags); |
| 198 | if (ctx) { |
| 199 | ++ctx->pin_count; |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 200 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 201 | } |
| 202 | return ctx; |
| 203 | } |
| 204 | |
| 205 | static void perf_unpin_context(struct perf_event_context *ctx) |
| 206 | { |
| 207 | unsigned long flags; |
| 208 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 209 | raw_spin_lock_irqsave(&ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 210 | --ctx->pin_count; |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 211 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 212 | put_ctx(ctx); |
| 213 | } |
| 214 | |
Peter Zijlstra | f67218c | 2009-11-23 11:37:27 +0100 | [diff] [blame] | 215 | static inline u64 perf_clock(void) |
| 216 | { |
Peter Zijlstra | 24691ea | 2010-02-26 16:36:23 +0100 | [diff] [blame] | 217 | return cpu_clock(raw_smp_processor_id()); |
Peter Zijlstra | f67218c | 2009-11-23 11:37:27 +0100 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | /* |
| 221 | * Update the record of the current time in a context. |
| 222 | */ |
| 223 | static void update_context_time(struct perf_event_context *ctx) |
| 224 | { |
| 225 | u64 now = perf_clock(); |
| 226 | |
| 227 | ctx->time += now - ctx->timestamp; |
| 228 | ctx->timestamp = now; |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * Update the total_time_enabled and total_time_running fields for a event. |
| 233 | */ |
| 234 | static void update_event_times(struct perf_event *event) |
| 235 | { |
| 236 | struct perf_event_context *ctx = event->ctx; |
| 237 | u64 run_end; |
| 238 | |
| 239 | if (event->state < PERF_EVENT_STATE_INACTIVE || |
| 240 | event->group_leader->state < PERF_EVENT_STATE_INACTIVE) |
| 241 | return; |
| 242 | |
Peter Zijlstra | acd1d7c | 2009-11-23 15:00:36 +0100 | [diff] [blame] | 243 | if (ctx->is_active) |
| 244 | run_end = ctx->time; |
| 245 | else |
| 246 | run_end = event->tstamp_stopped; |
| 247 | |
| 248 | event->total_time_enabled = run_end - event->tstamp_enabled; |
Peter Zijlstra | f67218c | 2009-11-23 11:37:27 +0100 | [diff] [blame] | 249 | |
| 250 | if (event->state == PERF_EVENT_STATE_INACTIVE) |
| 251 | run_end = event->tstamp_stopped; |
| 252 | else |
| 253 | run_end = ctx->time; |
| 254 | |
| 255 | event->total_time_running = run_end - event->tstamp_running; |
| 256 | } |
| 257 | |
Peter Zijlstra | 96c21a4 | 2010-05-11 16:19:10 +0200 | [diff] [blame] | 258 | /* |
| 259 | * Update total_time_enabled and total_time_running for all events in a group. |
| 260 | */ |
| 261 | static void update_group_times(struct perf_event *leader) |
| 262 | { |
| 263 | struct perf_event *event; |
| 264 | |
| 265 | update_event_times(leader); |
| 266 | list_for_each_entry(event, &leader->sibling_list, group_entry) |
| 267 | update_event_times(event); |
| 268 | } |
| 269 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 270 | static struct list_head * |
| 271 | ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) |
| 272 | { |
| 273 | if (event->attr.pinned) |
| 274 | return &ctx->pinned_groups; |
| 275 | else |
| 276 | return &ctx->flexible_groups; |
| 277 | } |
| 278 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 279 | /* |
| 280 | * Add a event from the lists for its context. |
| 281 | * Must be called with ctx->mutex and ctx->lock held. |
| 282 | */ |
| 283 | static void |
| 284 | list_add_event(struct perf_event *event, struct perf_event_context *ctx) |
| 285 | { |
| 286 | struct perf_event *group_leader = event->group_leader; |
| 287 | |
| 288 | /* |
| 289 | * Depending on whether it is a standalone or sibling event, |
| 290 | * add it straight to the context's event list, or to the group |
| 291 | * leader's sibling list: |
| 292 | */ |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 293 | if (group_leader == event) { |
| 294 | struct list_head *list; |
| 295 | |
Frederic Weisbecker | d6f962b | 2010-01-10 01:25:51 +0100 | [diff] [blame] | 296 | if (is_software_event(event)) |
| 297 | event->group_flags |= PERF_GROUP_SOFTWARE; |
| 298 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 299 | list = ctx_group_list(event, ctx); |
| 300 | list_add_tail(&event->group_entry, list); |
| 301 | } else { |
Frederic Weisbecker | d6f962b | 2010-01-10 01:25:51 +0100 | [diff] [blame] | 302 | if (group_leader->group_flags & PERF_GROUP_SOFTWARE && |
| 303 | !is_software_event(event)) |
| 304 | group_leader->group_flags &= ~PERF_GROUP_SOFTWARE; |
| 305 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 306 | list_add_tail(&event->group_entry, &group_leader->sibling_list); |
| 307 | group_leader->nr_siblings++; |
| 308 | } |
| 309 | |
| 310 | list_add_rcu(&event->event_entry, &ctx->event_list); |
| 311 | ctx->nr_events++; |
| 312 | if (event->attr.inherit_stat) |
| 313 | ctx->nr_stat++; |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Remove a event from the lists for its context. |
| 318 | * Must be called with ctx->mutex and ctx->lock held. |
| 319 | */ |
| 320 | static void |
| 321 | list_del_event(struct perf_event *event, struct perf_event_context *ctx) |
| 322 | { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 323 | if (list_empty(&event->group_entry)) |
| 324 | return; |
| 325 | ctx->nr_events--; |
| 326 | if (event->attr.inherit_stat) |
| 327 | ctx->nr_stat--; |
| 328 | |
| 329 | list_del_init(&event->group_entry); |
| 330 | list_del_rcu(&event->event_entry); |
| 331 | |
| 332 | if (event->group_leader != event) |
| 333 | event->group_leader->nr_siblings--; |
| 334 | |
Peter Zijlstra | 96c21a4 | 2010-05-11 16:19:10 +0200 | [diff] [blame] | 335 | update_group_times(event); |
Stephane Eranian | b2e74a2 | 2009-11-26 09:24:30 -0800 | [diff] [blame] | 336 | |
| 337 | /* |
| 338 | * If event was in error state, then keep it |
| 339 | * that way, otherwise bogus counts will be |
| 340 | * returned on read(). The only way to get out |
| 341 | * of error state is by explicit re-enabling |
| 342 | * of the event |
| 343 | */ |
| 344 | if (event->state > PERF_EVENT_STATE_OFF) |
| 345 | event->state = PERF_EVENT_STATE_OFF; |
Peter Zijlstra | 050735b | 2010-05-11 11:51:53 +0200 | [diff] [blame] | 346 | } |
| 347 | |
| 348 | static void |
| 349 | perf_destroy_group(struct perf_event *event, struct perf_event_context *ctx) |
| 350 | { |
| 351 | struct perf_event *sibling, *tmp; |
Peter Zijlstra | 2e2af50 | 2009-11-23 11:37:25 +0100 | [diff] [blame] | 352 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 353 | /* |
| 354 | * If this was a group event with sibling events then |
| 355 | * upgrade the siblings to singleton events by adding them |
| 356 | * to the context list directly: |
| 357 | */ |
| 358 | list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 359 | struct list_head *list; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 360 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 361 | list = ctx_group_list(event, ctx); |
| 362 | list_move_tail(&sibling->group_entry, list); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 363 | sibling->group_leader = sibling; |
Frederic Weisbecker | d6f962b | 2010-01-10 01:25:51 +0100 | [diff] [blame] | 364 | |
| 365 | /* Inherit group flags from the previous leader */ |
| 366 | sibling->group_flags = event->group_flags; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 367 | } |
| 368 | } |
| 369 | |
| 370 | static void |
| 371 | event_sched_out(struct perf_event *event, |
| 372 | struct perf_cpu_context *cpuctx, |
| 373 | struct perf_event_context *ctx) |
| 374 | { |
| 375 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
| 376 | return; |
| 377 | |
| 378 | event->state = PERF_EVENT_STATE_INACTIVE; |
| 379 | if (event->pending_disable) { |
| 380 | event->pending_disable = 0; |
| 381 | event->state = PERF_EVENT_STATE_OFF; |
| 382 | } |
| 383 | event->tstamp_stopped = ctx->time; |
| 384 | event->pmu->disable(event); |
| 385 | event->oncpu = -1; |
| 386 | |
| 387 | if (!is_software_event(event)) |
| 388 | cpuctx->active_oncpu--; |
| 389 | ctx->nr_active--; |
| 390 | if (event->attr.exclusive || !cpuctx->active_oncpu) |
| 391 | cpuctx->exclusive = 0; |
| 392 | } |
| 393 | |
| 394 | static void |
| 395 | group_sched_out(struct perf_event *group_event, |
| 396 | struct perf_cpu_context *cpuctx, |
| 397 | struct perf_event_context *ctx) |
| 398 | { |
| 399 | struct perf_event *event; |
| 400 | |
| 401 | if (group_event->state != PERF_EVENT_STATE_ACTIVE) |
| 402 | return; |
| 403 | |
| 404 | event_sched_out(group_event, cpuctx, ctx); |
| 405 | |
| 406 | /* |
| 407 | * Schedule out siblings (if any): |
| 408 | */ |
| 409 | list_for_each_entry(event, &group_event->sibling_list, group_entry) |
| 410 | event_sched_out(event, cpuctx, ctx); |
| 411 | |
| 412 | if (group_event->attr.exclusive) |
| 413 | cpuctx->exclusive = 0; |
| 414 | } |
| 415 | |
| 416 | /* |
| 417 | * Cross CPU call to remove a performance event |
| 418 | * |
| 419 | * We disable the event on the hardware level first. After that we |
| 420 | * remove it from the context list. |
| 421 | */ |
| 422 | static void __perf_event_remove_from_context(void *info) |
| 423 | { |
| 424 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 425 | struct perf_event *event = info; |
| 426 | struct perf_event_context *ctx = event->ctx; |
| 427 | |
| 428 | /* |
| 429 | * If this is a task context, we need to check whether it is |
| 430 | * the current task context of this cpu. If not it has been |
| 431 | * scheduled out before the smp call arrived. |
| 432 | */ |
| 433 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 434 | return; |
| 435 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 436 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 437 | /* |
| 438 | * Protect the list operation against NMI by disabling the |
| 439 | * events on a global level. |
| 440 | */ |
| 441 | perf_disable(); |
| 442 | |
| 443 | event_sched_out(event, cpuctx, ctx); |
| 444 | |
| 445 | list_del_event(event, ctx); |
| 446 | |
| 447 | if (!ctx->task) { |
| 448 | /* |
| 449 | * Allow more per task events with respect to the |
| 450 | * reservation: |
| 451 | */ |
| 452 | cpuctx->max_pertask = |
| 453 | min(perf_max_events - ctx->nr_events, |
| 454 | perf_max_events - perf_reserved_percpu); |
| 455 | } |
| 456 | |
| 457 | perf_enable(); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 458 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 459 | } |
| 460 | |
| 461 | |
| 462 | /* |
| 463 | * Remove the event from a task's (or a CPU's) list of events. |
| 464 | * |
| 465 | * Must be called with ctx->mutex held. |
| 466 | * |
| 467 | * CPU events are removed with a smp call. For task events we only |
| 468 | * call when the task is on a CPU. |
| 469 | * |
| 470 | * If event->ctx is a cloned context, callers must make sure that |
| 471 | * every task struct that event->ctx->task could possibly point to |
| 472 | * remains valid. This is OK when called from perf_release since |
| 473 | * that only calls us on the top-level context, which can't be a clone. |
| 474 | * When called from perf_event_exit_task, it's OK because the |
| 475 | * context has been detached from its task. |
| 476 | */ |
| 477 | static void perf_event_remove_from_context(struct perf_event *event) |
| 478 | { |
| 479 | struct perf_event_context *ctx = event->ctx; |
| 480 | struct task_struct *task = ctx->task; |
| 481 | |
| 482 | if (!task) { |
| 483 | /* |
| 484 | * Per cpu events are removed via an smp call and |
André Goddard Rosa | af901ca | 2009-11-14 13:09:05 -0200 | [diff] [blame] | 485 | * the removal is always successful. |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 486 | */ |
| 487 | smp_call_function_single(event->cpu, |
| 488 | __perf_event_remove_from_context, |
| 489 | event, 1); |
| 490 | return; |
| 491 | } |
| 492 | |
| 493 | retry: |
| 494 | task_oncpu_function_call(task, __perf_event_remove_from_context, |
| 495 | event); |
| 496 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 497 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 498 | /* |
| 499 | * If the context is active we need to retry the smp call. |
| 500 | */ |
| 501 | if (ctx->nr_active && !list_empty(&event->group_entry)) { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 502 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 503 | goto retry; |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * The lock prevents that this context is scheduled in so we |
| 508 | * can remove the event safely, if the call above did not |
| 509 | * succeed. |
| 510 | */ |
Peter Zijlstra | 6c2bfcb | 2009-11-23 11:37:24 +0100 | [diff] [blame] | 511 | if (!list_empty(&event->group_entry)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 512 | list_del_event(event, ctx); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 513 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 514 | } |
| 515 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 516 | /* |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 517 | * Cross CPU call to disable a performance event |
| 518 | */ |
| 519 | static void __perf_event_disable(void *info) |
| 520 | { |
| 521 | struct perf_event *event = info; |
| 522 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 523 | struct perf_event_context *ctx = event->ctx; |
| 524 | |
| 525 | /* |
| 526 | * If this is a per-task event, need to check whether this |
| 527 | * event's task is the current task on this cpu. |
| 528 | */ |
| 529 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 530 | return; |
| 531 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 532 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 533 | |
| 534 | /* |
| 535 | * If the event is on, turn it off. |
| 536 | * If it is in error state, leave it in error state. |
| 537 | */ |
| 538 | if (event->state >= PERF_EVENT_STATE_INACTIVE) { |
| 539 | update_context_time(ctx); |
| 540 | update_group_times(event); |
| 541 | if (event == event->group_leader) |
| 542 | group_sched_out(event, cpuctx, ctx); |
| 543 | else |
| 544 | event_sched_out(event, cpuctx, ctx); |
| 545 | event->state = PERF_EVENT_STATE_OFF; |
| 546 | } |
| 547 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 548 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 549 | } |
| 550 | |
| 551 | /* |
| 552 | * Disable a event. |
| 553 | * |
| 554 | * If event->ctx is a cloned context, callers must make sure that |
| 555 | * every task struct that event->ctx->task could possibly point to |
| 556 | * remains valid. This condition is satisifed when called through |
| 557 | * perf_event_for_each_child or perf_event_for_each because they |
| 558 | * hold the top-level event's child_mutex, so any descendant that |
| 559 | * goes to exit will block in sync_child_event. |
| 560 | * When called from perf_pending_event it's OK because event->ctx |
| 561 | * is the current context on this CPU and preemption is disabled, |
| 562 | * hence we can't get into perf_event_task_sched_out for this context. |
| 563 | */ |
Frederic Weisbecker | 44234ad | 2009-12-09 09:25:48 +0100 | [diff] [blame] | 564 | void perf_event_disable(struct perf_event *event) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 565 | { |
| 566 | struct perf_event_context *ctx = event->ctx; |
| 567 | struct task_struct *task = ctx->task; |
| 568 | |
| 569 | if (!task) { |
| 570 | /* |
| 571 | * Disable the event on the cpu that it's on |
| 572 | */ |
| 573 | smp_call_function_single(event->cpu, __perf_event_disable, |
| 574 | event, 1); |
| 575 | return; |
| 576 | } |
| 577 | |
| 578 | retry: |
| 579 | task_oncpu_function_call(task, __perf_event_disable, event); |
| 580 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 581 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 582 | /* |
| 583 | * If the event is still active, we need to retry the cross-call. |
| 584 | */ |
| 585 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 586 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 587 | goto retry; |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * Since we have the lock this context can't be scheduled |
| 592 | * in, so we can change the state safely. |
| 593 | */ |
| 594 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
| 595 | update_group_times(event); |
| 596 | event->state = PERF_EVENT_STATE_OFF; |
| 597 | } |
| 598 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 599 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 600 | } |
| 601 | |
| 602 | static int |
| 603 | event_sched_in(struct perf_event *event, |
| 604 | struct perf_cpu_context *cpuctx, |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 605 | struct perf_event_context *ctx) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 606 | { |
| 607 | if (event->state <= PERF_EVENT_STATE_OFF) |
| 608 | return 0; |
| 609 | |
| 610 | event->state = PERF_EVENT_STATE_ACTIVE; |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 611 | event->oncpu = smp_processor_id(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 612 | /* |
| 613 | * The new state must be visible before we turn it on in the hardware: |
| 614 | */ |
| 615 | smp_wmb(); |
| 616 | |
| 617 | if (event->pmu->enable(event)) { |
| 618 | event->state = PERF_EVENT_STATE_INACTIVE; |
| 619 | event->oncpu = -1; |
| 620 | return -EAGAIN; |
| 621 | } |
| 622 | |
| 623 | event->tstamp_running += ctx->time - event->tstamp_stopped; |
| 624 | |
| 625 | if (!is_software_event(event)) |
| 626 | cpuctx->active_oncpu++; |
| 627 | ctx->nr_active++; |
| 628 | |
| 629 | if (event->attr.exclusive) |
| 630 | cpuctx->exclusive = 1; |
| 631 | |
| 632 | return 0; |
| 633 | } |
| 634 | |
| 635 | static int |
| 636 | group_sched_in(struct perf_event *group_event, |
| 637 | struct perf_cpu_context *cpuctx, |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 638 | struct perf_event_context *ctx) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 639 | { |
Lin Ming | 6bde9b6 | 2010-04-23 13:56:00 +0800 | [diff] [blame] | 640 | struct perf_event *event, *partial_group = NULL; |
| 641 | const struct pmu *pmu = group_event->pmu; |
| 642 | bool txn = false; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 643 | int ret; |
| 644 | |
| 645 | if (group_event->state == PERF_EVENT_STATE_OFF) |
| 646 | return 0; |
| 647 | |
Lin Ming | 6bde9b6 | 2010-04-23 13:56:00 +0800 | [diff] [blame] | 648 | /* Check if group transaction availabe */ |
| 649 | if (pmu->start_txn) |
| 650 | txn = true; |
| 651 | |
| 652 | if (txn) |
| 653 | pmu->start_txn(pmu); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 654 | |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 655 | if (event_sched_in(group_event, cpuctx, ctx)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 656 | return -EAGAIN; |
| 657 | |
| 658 | /* |
| 659 | * Schedule in siblings as one group (if any): |
| 660 | */ |
| 661 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 662 | if (event_sched_in(event, cpuctx, ctx)) { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 663 | partial_group = event; |
| 664 | goto group_error; |
| 665 | } |
| 666 | } |
| 667 | |
Paul Mackerras | 6e85158 | 2010-05-08 20:58:00 +1000 | [diff] [blame] | 668 | if (!txn) |
| 669 | return 0; |
Lin Ming | 6bde9b6 | 2010-04-23 13:56:00 +0800 | [diff] [blame] | 670 | |
Paul Mackerras | 6e85158 | 2010-05-08 20:58:00 +1000 | [diff] [blame] | 671 | ret = pmu->commit_txn(pmu); |
| 672 | if (!ret) { |
| 673 | pmu->cancel_txn(pmu); |
| 674 | return 0; |
Lin Ming | 6bde9b6 | 2010-04-23 13:56:00 +0800 | [diff] [blame] | 675 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 676 | |
| 677 | group_error: |
Lin Ming | 6bde9b6 | 2010-04-23 13:56:00 +0800 | [diff] [blame] | 678 | if (txn) |
| 679 | pmu->cancel_txn(pmu); |
| 680 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 681 | /* |
| 682 | * Groups can be scheduled in as one unit only, so undo any |
| 683 | * partial group before returning: |
| 684 | */ |
| 685 | list_for_each_entry(event, &group_event->sibling_list, group_entry) { |
| 686 | if (event == partial_group) |
| 687 | break; |
| 688 | event_sched_out(event, cpuctx, ctx); |
| 689 | } |
| 690 | event_sched_out(group_event, cpuctx, ctx); |
| 691 | |
| 692 | return -EAGAIN; |
| 693 | } |
| 694 | |
| 695 | /* |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 696 | * Work out whether we can put this event group on the CPU now. |
| 697 | */ |
| 698 | static int group_can_go_on(struct perf_event *event, |
| 699 | struct perf_cpu_context *cpuctx, |
| 700 | int can_add_hw) |
| 701 | { |
| 702 | /* |
| 703 | * Groups consisting entirely of software events can always go on. |
| 704 | */ |
Frederic Weisbecker | d6f962b | 2010-01-10 01:25:51 +0100 | [diff] [blame] | 705 | if (event->group_flags & PERF_GROUP_SOFTWARE) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 706 | return 1; |
| 707 | /* |
| 708 | * If an exclusive group is already on, no other hardware |
| 709 | * events can go on. |
| 710 | */ |
| 711 | if (cpuctx->exclusive) |
| 712 | return 0; |
| 713 | /* |
| 714 | * If this group is exclusive and there are already |
| 715 | * events on the CPU, it can't go on. |
| 716 | */ |
| 717 | if (event->attr.exclusive && cpuctx->active_oncpu) |
| 718 | return 0; |
| 719 | /* |
| 720 | * Otherwise, try to add it if all previous groups were able |
| 721 | * to go on. |
| 722 | */ |
| 723 | return can_add_hw; |
| 724 | } |
| 725 | |
| 726 | static void add_event_to_ctx(struct perf_event *event, |
| 727 | struct perf_event_context *ctx) |
| 728 | { |
| 729 | list_add_event(event, ctx); |
| 730 | event->tstamp_enabled = ctx->time; |
| 731 | event->tstamp_running = ctx->time; |
| 732 | event->tstamp_stopped = ctx->time; |
| 733 | } |
| 734 | |
| 735 | /* |
| 736 | * Cross CPU call to install and enable a performance event |
| 737 | * |
| 738 | * Must be called with ctx->mutex held |
| 739 | */ |
| 740 | static void __perf_install_in_context(void *info) |
| 741 | { |
| 742 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 743 | struct perf_event *event = info; |
| 744 | struct perf_event_context *ctx = event->ctx; |
| 745 | struct perf_event *leader = event->group_leader; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 746 | int err; |
| 747 | |
| 748 | /* |
| 749 | * If this is a task context, we need to check whether it is |
| 750 | * the current task context of this cpu. If not it has been |
| 751 | * scheduled out before the smp call arrived. |
| 752 | * Or possibly this is the right context but it isn't |
| 753 | * on this cpu because it had no events. |
| 754 | */ |
| 755 | if (ctx->task && cpuctx->task_ctx != ctx) { |
| 756 | if (cpuctx->task_ctx || ctx->task != current) |
| 757 | return; |
| 758 | cpuctx->task_ctx = ctx; |
| 759 | } |
| 760 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 761 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 762 | ctx->is_active = 1; |
| 763 | update_context_time(ctx); |
| 764 | |
| 765 | /* |
| 766 | * Protect the list operation against NMI by disabling the |
| 767 | * events on a global level. NOP for non NMI based events. |
| 768 | */ |
| 769 | perf_disable(); |
| 770 | |
| 771 | add_event_to_ctx(event, ctx); |
| 772 | |
Peter Zijlstra | f4c4176 | 2009-12-16 17:55:54 +0100 | [diff] [blame] | 773 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 774 | goto unlock; |
| 775 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 776 | /* |
| 777 | * Don't put the event on if it is disabled or if |
| 778 | * it is in a group and the group isn't on. |
| 779 | */ |
| 780 | if (event->state != PERF_EVENT_STATE_INACTIVE || |
| 781 | (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)) |
| 782 | goto unlock; |
| 783 | |
| 784 | /* |
| 785 | * An exclusive event can't go on if there are already active |
| 786 | * hardware events, and no hardware event can go on if there |
| 787 | * is already an exclusive event on. |
| 788 | */ |
| 789 | if (!group_can_go_on(event, cpuctx, 1)) |
| 790 | err = -EEXIST; |
| 791 | else |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 792 | err = event_sched_in(event, cpuctx, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 793 | |
| 794 | if (err) { |
| 795 | /* |
| 796 | * This event couldn't go on. If it is in a group |
| 797 | * then we have to pull the whole group off. |
| 798 | * If the event group is pinned then put it in error state. |
| 799 | */ |
| 800 | if (leader != event) |
| 801 | group_sched_out(leader, cpuctx, ctx); |
| 802 | if (leader->attr.pinned) { |
| 803 | update_group_times(leader); |
| 804 | leader->state = PERF_EVENT_STATE_ERROR; |
| 805 | } |
| 806 | } |
| 807 | |
| 808 | if (!err && !ctx->task && cpuctx->max_pertask) |
| 809 | cpuctx->max_pertask--; |
| 810 | |
| 811 | unlock: |
| 812 | perf_enable(); |
| 813 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 814 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 815 | } |
| 816 | |
| 817 | /* |
| 818 | * Attach a performance event to a context |
| 819 | * |
| 820 | * First we add the event to the list with the hardware enable bit |
| 821 | * in event->hw_config cleared. |
| 822 | * |
| 823 | * If the event is attached to a task which is on a CPU we use a smp |
| 824 | * call to enable it in the task context. The task might have been |
| 825 | * scheduled away, but we check this in the smp call again. |
| 826 | * |
| 827 | * Must be called with ctx->mutex held. |
| 828 | */ |
| 829 | static void |
| 830 | perf_install_in_context(struct perf_event_context *ctx, |
| 831 | struct perf_event *event, |
| 832 | int cpu) |
| 833 | { |
| 834 | struct task_struct *task = ctx->task; |
| 835 | |
| 836 | if (!task) { |
| 837 | /* |
| 838 | * Per cpu events are installed via an smp call and |
André Goddard Rosa | af901ca | 2009-11-14 13:09:05 -0200 | [diff] [blame] | 839 | * the install is always successful. |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 840 | */ |
| 841 | smp_call_function_single(cpu, __perf_install_in_context, |
| 842 | event, 1); |
| 843 | return; |
| 844 | } |
| 845 | |
| 846 | retry: |
| 847 | task_oncpu_function_call(task, __perf_install_in_context, |
| 848 | event); |
| 849 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 850 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 851 | /* |
| 852 | * we need to retry the smp call. |
| 853 | */ |
| 854 | if (ctx->is_active && list_empty(&event->group_entry)) { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 855 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 856 | goto retry; |
| 857 | } |
| 858 | |
| 859 | /* |
| 860 | * The lock prevents that this context is scheduled in so we |
| 861 | * can add the event safely, if it the call above did not |
| 862 | * succeed. |
| 863 | */ |
| 864 | if (list_empty(&event->group_entry)) |
| 865 | add_event_to_ctx(event, ctx); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 866 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 867 | } |
| 868 | |
| 869 | /* |
| 870 | * Put a event into inactive state and update time fields. |
| 871 | * Enabling the leader of a group effectively enables all |
| 872 | * the group members that aren't explicitly disabled, so we |
| 873 | * have to update their ->tstamp_enabled also. |
| 874 | * Note: this works for group members as well as group leaders |
| 875 | * since the non-leader members' sibling_lists will be empty. |
| 876 | */ |
| 877 | static void __perf_event_mark_enabled(struct perf_event *event, |
| 878 | struct perf_event_context *ctx) |
| 879 | { |
| 880 | struct perf_event *sub; |
| 881 | |
| 882 | event->state = PERF_EVENT_STATE_INACTIVE; |
| 883 | event->tstamp_enabled = ctx->time - event->total_time_enabled; |
| 884 | list_for_each_entry(sub, &event->sibling_list, group_entry) |
| 885 | if (sub->state >= PERF_EVENT_STATE_INACTIVE) |
| 886 | sub->tstamp_enabled = |
| 887 | ctx->time - sub->total_time_enabled; |
| 888 | } |
| 889 | |
| 890 | /* |
| 891 | * Cross CPU call to enable a performance event |
| 892 | */ |
| 893 | static void __perf_event_enable(void *info) |
| 894 | { |
| 895 | struct perf_event *event = info; |
| 896 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 897 | struct perf_event_context *ctx = event->ctx; |
| 898 | struct perf_event *leader = event->group_leader; |
| 899 | int err; |
| 900 | |
| 901 | /* |
| 902 | * If this is a per-task event, need to check whether this |
| 903 | * event's task is the current task on this cpu. |
| 904 | */ |
| 905 | if (ctx->task && cpuctx->task_ctx != ctx) { |
| 906 | if (cpuctx->task_ctx || ctx->task != current) |
| 907 | return; |
| 908 | cpuctx->task_ctx = ctx; |
| 909 | } |
| 910 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 911 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 912 | ctx->is_active = 1; |
| 913 | update_context_time(ctx); |
| 914 | |
| 915 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
| 916 | goto unlock; |
| 917 | __perf_event_mark_enabled(event, ctx); |
| 918 | |
Peter Zijlstra | f4c4176 | 2009-12-16 17:55:54 +0100 | [diff] [blame] | 919 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 920 | goto unlock; |
| 921 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 922 | /* |
| 923 | * If the event is in a group and isn't the group leader, |
| 924 | * then don't put it on unless the group is on. |
| 925 | */ |
| 926 | if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) |
| 927 | goto unlock; |
| 928 | |
| 929 | if (!group_can_go_on(event, cpuctx, 1)) { |
| 930 | err = -EEXIST; |
| 931 | } else { |
| 932 | perf_disable(); |
| 933 | if (event == leader) |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 934 | err = group_sched_in(event, cpuctx, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 935 | else |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 936 | err = event_sched_in(event, cpuctx, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 937 | perf_enable(); |
| 938 | } |
| 939 | |
| 940 | if (err) { |
| 941 | /* |
| 942 | * If this event can't go on and it's part of a |
| 943 | * group, then the whole group has to come off. |
| 944 | */ |
| 945 | if (leader != event) |
| 946 | group_sched_out(leader, cpuctx, ctx); |
| 947 | if (leader->attr.pinned) { |
| 948 | update_group_times(leader); |
| 949 | leader->state = PERF_EVENT_STATE_ERROR; |
| 950 | } |
| 951 | } |
| 952 | |
| 953 | unlock: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 954 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 955 | } |
| 956 | |
| 957 | /* |
| 958 | * Enable a event. |
| 959 | * |
| 960 | * If event->ctx is a cloned context, callers must make sure that |
| 961 | * every task struct that event->ctx->task could possibly point to |
| 962 | * remains valid. This condition is satisfied when called through |
| 963 | * perf_event_for_each_child or perf_event_for_each as described |
| 964 | * for perf_event_disable. |
| 965 | */ |
Frederic Weisbecker | 44234ad | 2009-12-09 09:25:48 +0100 | [diff] [blame] | 966 | void perf_event_enable(struct perf_event *event) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 967 | { |
| 968 | struct perf_event_context *ctx = event->ctx; |
| 969 | struct task_struct *task = ctx->task; |
| 970 | |
| 971 | if (!task) { |
| 972 | /* |
| 973 | * Enable the event on the cpu that it's on |
| 974 | */ |
| 975 | smp_call_function_single(event->cpu, __perf_event_enable, |
| 976 | event, 1); |
| 977 | return; |
| 978 | } |
| 979 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 980 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 981 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
| 982 | goto out; |
| 983 | |
| 984 | /* |
| 985 | * If the event is in error state, clear that first. |
| 986 | * That way, if we see the event in error state below, we |
| 987 | * know that it has gone back into error state, as distinct |
| 988 | * from the task having been scheduled away before the |
| 989 | * cross-call arrived. |
| 990 | */ |
| 991 | if (event->state == PERF_EVENT_STATE_ERROR) |
| 992 | event->state = PERF_EVENT_STATE_OFF; |
| 993 | |
| 994 | retry: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 995 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 996 | task_oncpu_function_call(task, __perf_event_enable, event); |
| 997 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 998 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 999 | |
| 1000 | /* |
| 1001 | * If the context is active and the event is still off, |
| 1002 | * we need to retry the cross-call. |
| 1003 | */ |
| 1004 | if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) |
| 1005 | goto retry; |
| 1006 | |
| 1007 | /* |
| 1008 | * Since we have the lock this context can't be scheduled |
| 1009 | * in, so we can change the state safely. |
| 1010 | */ |
| 1011 | if (event->state == PERF_EVENT_STATE_OFF) |
| 1012 | __perf_event_mark_enabled(event, ctx); |
| 1013 | |
| 1014 | out: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1015 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1016 | } |
| 1017 | |
| 1018 | static int perf_event_refresh(struct perf_event *event, int refresh) |
| 1019 | { |
| 1020 | /* |
| 1021 | * not supported on inherited events |
| 1022 | */ |
| 1023 | if (event->attr.inherit) |
| 1024 | return -EINVAL; |
| 1025 | |
| 1026 | atomic_add(refresh, &event->event_limit); |
| 1027 | perf_event_enable(event); |
| 1028 | |
| 1029 | return 0; |
| 1030 | } |
| 1031 | |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1032 | enum event_type_t { |
| 1033 | EVENT_FLEXIBLE = 0x1, |
| 1034 | EVENT_PINNED = 0x2, |
| 1035 | EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, |
| 1036 | }; |
| 1037 | |
| 1038 | static void ctx_sched_out(struct perf_event_context *ctx, |
| 1039 | struct perf_cpu_context *cpuctx, |
| 1040 | enum event_type_t event_type) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1041 | { |
| 1042 | struct perf_event *event; |
| 1043 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1044 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1045 | ctx->is_active = 0; |
| 1046 | if (likely(!ctx->nr_events)) |
| 1047 | goto out; |
| 1048 | update_context_time(ctx); |
| 1049 | |
| 1050 | perf_disable(); |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1051 | if (!ctx->nr_active) |
| 1052 | goto out_enable; |
| 1053 | |
| 1054 | if (event_type & EVENT_PINNED) |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1055 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) |
| 1056 | group_sched_out(event, cpuctx, ctx); |
| 1057 | |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1058 | if (event_type & EVENT_FLEXIBLE) |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1059 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) |
Xiao Guangrong | 8c9ed8e | 2009-09-25 13:51:17 +0800 | [diff] [blame] | 1060 | group_sched_out(event, cpuctx, ctx); |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1061 | |
| 1062 | out_enable: |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1063 | perf_enable(); |
| 1064 | out: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1065 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1066 | } |
| 1067 | |
| 1068 | /* |
| 1069 | * Test whether two contexts are equivalent, i.e. whether they |
| 1070 | * have both been cloned from the same version of the same context |
| 1071 | * and they both have the same number of enabled events. |
| 1072 | * If the number of enabled events is the same, then the set |
| 1073 | * of enabled events should be the same, because these are both |
| 1074 | * inherited contexts, therefore we can't access individual events |
| 1075 | * in them directly with an fd; we can only enable/disable all |
| 1076 | * events via prctl, or enable/disable all events in a family |
| 1077 | * via ioctl, which will have the same effect on both contexts. |
| 1078 | */ |
| 1079 | static int context_equiv(struct perf_event_context *ctx1, |
| 1080 | struct perf_event_context *ctx2) |
| 1081 | { |
| 1082 | return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx |
| 1083 | && ctx1->parent_gen == ctx2->parent_gen |
| 1084 | && !ctx1->pin_count && !ctx2->pin_count; |
| 1085 | } |
| 1086 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1087 | static void __perf_event_sync_stat(struct perf_event *event, |
| 1088 | struct perf_event *next_event) |
| 1089 | { |
| 1090 | u64 value; |
| 1091 | |
| 1092 | if (!event->attr.inherit_stat) |
| 1093 | return; |
| 1094 | |
| 1095 | /* |
| 1096 | * Update the event value, we cannot use perf_event_read() |
| 1097 | * because we're in the middle of a context switch and have IRQs |
| 1098 | * disabled, which upsets smp_call_function_single(), however |
| 1099 | * we know the event must be on the current CPU, therefore we |
| 1100 | * don't need to use it. |
| 1101 | */ |
| 1102 | switch (event->state) { |
| 1103 | case PERF_EVENT_STATE_ACTIVE: |
Peter Zijlstra | 3dbebf1 | 2009-11-20 22:19:52 +0100 | [diff] [blame] | 1104 | event->pmu->read(event); |
| 1105 | /* fall-through */ |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1106 | |
| 1107 | case PERF_EVENT_STATE_INACTIVE: |
| 1108 | update_event_times(event); |
| 1109 | break; |
| 1110 | |
| 1111 | default: |
| 1112 | break; |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * In order to keep per-task stats reliable we need to flip the event |
| 1117 | * values when we flip the contexts. |
| 1118 | */ |
| 1119 | value = atomic64_read(&next_event->count); |
| 1120 | value = atomic64_xchg(&event->count, value); |
| 1121 | atomic64_set(&next_event->count, value); |
| 1122 | |
| 1123 | swap(event->total_time_enabled, next_event->total_time_enabled); |
| 1124 | swap(event->total_time_running, next_event->total_time_running); |
| 1125 | |
| 1126 | /* |
| 1127 | * Since we swizzled the values, update the user visible data too. |
| 1128 | */ |
| 1129 | perf_event_update_userpage(event); |
| 1130 | perf_event_update_userpage(next_event); |
| 1131 | } |
| 1132 | |
| 1133 | #define list_next_entry(pos, member) \ |
| 1134 | list_entry(pos->member.next, typeof(*pos), member) |
| 1135 | |
| 1136 | static void perf_event_sync_stat(struct perf_event_context *ctx, |
| 1137 | struct perf_event_context *next_ctx) |
| 1138 | { |
| 1139 | struct perf_event *event, *next_event; |
| 1140 | |
| 1141 | if (!ctx->nr_stat) |
| 1142 | return; |
| 1143 | |
Peter Zijlstra | 02ffdbc | 2009-11-20 22:19:50 +0100 | [diff] [blame] | 1144 | update_context_time(ctx); |
| 1145 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1146 | event = list_first_entry(&ctx->event_list, |
| 1147 | struct perf_event, event_entry); |
| 1148 | |
| 1149 | next_event = list_first_entry(&next_ctx->event_list, |
| 1150 | struct perf_event, event_entry); |
| 1151 | |
| 1152 | while (&event->event_entry != &ctx->event_list && |
| 1153 | &next_event->event_entry != &next_ctx->event_list) { |
| 1154 | |
| 1155 | __perf_event_sync_stat(event, next_event); |
| 1156 | |
| 1157 | event = list_next_entry(event, event_entry); |
| 1158 | next_event = list_next_entry(next_event, event_entry); |
| 1159 | } |
| 1160 | } |
| 1161 | |
| 1162 | /* |
| 1163 | * Called from scheduler to remove the events of the current task, |
| 1164 | * with interrupts disabled. |
| 1165 | * |
| 1166 | * We stop each event and update the event value in event->count. |
| 1167 | * |
| 1168 | * This does not protect us against NMI, but disable() |
| 1169 | * sets the disabled bit in the control field of event _before_ |
| 1170 | * accessing the event control register. If a NMI hits, then it will |
| 1171 | * not restart the event. |
| 1172 | */ |
| 1173 | void perf_event_task_sched_out(struct task_struct *task, |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1174 | struct task_struct *next) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1175 | { |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1176 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1177 | struct perf_event_context *ctx = task->perf_event_ctxp; |
| 1178 | struct perf_event_context *next_ctx; |
| 1179 | struct perf_event_context *parent; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1180 | int do_switch = 1; |
| 1181 | |
Frederic Weisbecker | e49a5bd | 2010-03-22 19:40:03 +0100 | [diff] [blame] | 1182 | perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1183 | |
| 1184 | if (likely(!ctx || !cpuctx->task_ctx)) |
| 1185 | return; |
| 1186 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1187 | rcu_read_lock(); |
| 1188 | parent = rcu_dereference(ctx->parent_ctx); |
| 1189 | next_ctx = next->perf_event_ctxp; |
| 1190 | if (parent && next_ctx && |
| 1191 | rcu_dereference(next_ctx->parent_ctx) == parent) { |
| 1192 | /* |
| 1193 | * Looks like the two contexts are clones, so we might be |
| 1194 | * able to optimize the context switch. We lock both |
| 1195 | * contexts and check that they are clones under the |
| 1196 | * lock (including re-checking that neither has been |
| 1197 | * uncloned in the meantime). It doesn't matter which |
| 1198 | * order we take the locks because no other cpu could |
| 1199 | * be trying to lock both of these tasks. |
| 1200 | */ |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1201 | raw_spin_lock(&ctx->lock); |
| 1202 | raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1203 | if (context_equiv(ctx, next_ctx)) { |
| 1204 | /* |
| 1205 | * XXX do we need a memory barrier of sorts |
| 1206 | * wrt to rcu_dereference() of perf_event_ctxp |
| 1207 | */ |
| 1208 | task->perf_event_ctxp = next_ctx; |
| 1209 | next->perf_event_ctxp = ctx; |
| 1210 | ctx->task = next; |
| 1211 | next_ctx->task = task; |
| 1212 | do_switch = 0; |
| 1213 | |
| 1214 | perf_event_sync_stat(ctx, next_ctx); |
| 1215 | } |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1216 | raw_spin_unlock(&next_ctx->lock); |
| 1217 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1218 | } |
| 1219 | rcu_read_unlock(); |
| 1220 | |
| 1221 | if (do_switch) { |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1222 | ctx_sched_out(ctx, cpuctx, EVENT_ALL); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1223 | cpuctx->task_ctx = NULL; |
| 1224 | } |
| 1225 | } |
| 1226 | |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1227 | static void task_ctx_sched_out(struct perf_event_context *ctx, |
| 1228 | enum event_type_t event_type) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1229 | { |
| 1230 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1231 | |
| 1232 | if (!cpuctx->task_ctx) |
| 1233 | return; |
| 1234 | |
| 1235 | if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) |
| 1236 | return; |
| 1237 | |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1238 | ctx_sched_out(ctx, cpuctx, event_type); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1239 | cpuctx->task_ctx = NULL; |
| 1240 | } |
| 1241 | |
| 1242 | /* |
| 1243 | * Called with IRQs disabled |
| 1244 | */ |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1245 | static void __perf_event_task_sched_out(struct perf_event_context *ctx) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1246 | { |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1247 | task_ctx_sched_out(ctx, EVENT_ALL); |
| 1248 | } |
| 1249 | |
| 1250 | /* |
| 1251 | * Called with IRQs disabled |
| 1252 | */ |
| 1253 | static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx, |
| 1254 | enum event_type_t event_type) |
| 1255 | { |
| 1256 | ctx_sched_out(&cpuctx->ctx, cpuctx, event_type); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1257 | } |
| 1258 | |
| 1259 | static void |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1260 | ctx_pinned_sched_in(struct perf_event_context *ctx, |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1261 | struct perf_cpu_context *cpuctx) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1262 | { |
| 1263 | struct perf_event *event; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1264 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1265 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
| 1266 | if (event->state <= PERF_EVENT_STATE_OFF) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1267 | continue; |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1268 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1269 | continue; |
| 1270 | |
Xiao Guangrong | 8c9ed8e | 2009-09-25 13:51:17 +0800 | [diff] [blame] | 1271 | if (group_can_go_on(event, cpuctx, 1)) |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1272 | group_sched_in(event, cpuctx, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1273 | |
| 1274 | /* |
| 1275 | * If this pinned group hasn't been scheduled, |
| 1276 | * put it in error state. |
| 1277 | */ |
| 1278 | if (event->state == PERF_EVENT_STATE_INACTIVE) { |
| 1279 | update_group_times(event); |
| 1280 | event->state = PERF_EVENT_STATE_ERROR; |
| 1281 | } |
| 1282 | } |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1283 | } |
| 1284 | |
| 1285 | static void |
| 1286 | ctx_flexible_sched_in(struct perf_event_context *ctx, |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1287 | struct perf_cpu_context *cpuctx) |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1288 | { |
| 1289 | struct perf_event *event; |
| 1290 | int can_add_hw = 1; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1291 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1292 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
| 1293 | /* Ignore events in OFF or ERROR state */ |
| 1294 | if (event->state <= PERF_EVENT_STATE_OFF) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1295 | continue; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1296 | /* |
| 1297 | * Listen to the 'cpu' scheduling filter constraint |
| 1298 | * of events: |
| 1299 | */ |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1300 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1301 | continue; |
| 1302 | |
Xiao Guangrong | 8c9ed8e | 2009-09-25 13:51:17 +0800 | [diff] [blame] | 1303 | if (group_can_go_on(event, cpuctx, can_add_hw)) |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1304 | if (group_sched_in(event, cpuctx, ctx)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1305 | can_add_hw = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1306 | } |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1307 | } |
| 1308 | |
| 1309 | static void |
| 1310 | ctx_sched_in(struct perf_event_context *ctx, |
| 1311 | struct perf_cpu_context *cpuctx, |
| 1312 | enum event_type_t event_type) |
| 1313 | { |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1314 | raw_spin_lock(&ctx->lock); |
| 1315 | ctx->is_active = 1; |
| 1316 | if (likely(!ctx->nr_events)) |
| 1317 | goto out; |
| 1318 | |
| 1319 | ctx->timestamp = perf_clock(); |
| 1320 | |
| 1321 | perf_disable(); |
| 1322 | |
| 1323 | /* |
| 1324 | * First go through the list and put on any pinned groups |
| 1325 | * in order to give them the best chance of going on. |
| 1326 | */ |
| 1327 | if (event_type & EVENT_PINNED) |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1328 | ctx_pinned_sched_in(ctx, cpuctx); |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1329 | |
| 1330 | /* Then walk through the lower prio flexible groups */ |
| 1331 | if (event_type & EVENT_FLEXIBLE) |
Peter Zijlstra | 6e37738 | 2010-02-11 13:21:58 +0100 | [diff] [blame] | 1332 | ctx_flexible_sched_in(ctx, cpuctx); |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1333 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1334 | perf_enable(); |
| 1335 | out: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1336 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1337 | } |
| 1338 | |
Frederic Weisbecker | 329c0e0 | 2010-01-17 12:56:05 +0100 | [diff] [blame] | 1339 | static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx, |
| 1340 | enum event_type_t event_type) |
| 1341 | { |
| 1342 | struct perf_event_context *ctx = &cpuctx->ctx; |
| 1343 | |
| 1344 | ctx_sched_in(ctx, cpuctx, event_type); |
| 1345 | } |
| 1346 | |
Frederic Weisbecker | 5b0311e | 2010-01-17 11:59:13 +0100 | [diff] [blame] | 1347 | static void task_ctx_sched_in(struct task_struct *task, |
| 1348 | enum event_type_t event_type) |
| 1349 | { |
| 1350 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1351 | struct perf_event_context *ctx = task->perf_event_ctxp; |
| 1352 | |
| 1353 | if (likely(!ctx)) |
| 1354 | return; |
| 1355 | if (cpuctx->task_ctx == ctx) |
| 1356 | return; |
| 1357 | ctx_sched_in(ctx, cpuctx, event_type); |
| 1358 | cpuctx->task_ctx = ctx; |
| 1359 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1360 | /* |
| 1361 | * Called from scheduler to add the events of the current task |
| 1362 | * with interrupts disabled. |
| 1363 | * |
| 1364 | * We restore the event value and then enable it. |
| 1365 | * |
| 1366 | * This does not protect us against NMI, but enable() |
| 1367 | * sets the enabled bit in the control field of event _before_ |
| 1368 | * accessing the event control register. If a NMI hits, then it will |
| 1369 | * keep the event running. |
| 1370 | */ |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1371 | void perf_event_task_sched_in(struct task_struct *task) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1372 | { |
Frederic Weisbecker | 329c0e0 | 2010-01-17 12:56:05 +0100 | [diff] [blame] | 1373 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1374 | struct perf_event_context *ctx = task->perf_event_ctxp; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1375 | |
Frederic Weisbecker | 329c0e0 | 2010-01-17 12:56:05 +0100 | [diff] [blame] | 1376 | if (likely(!ctx)) |
| 1377 | return; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1378 | |
Frederic Weisbecker | 329c0e0 | 2010-01-17 12:56:05 +0100 | [diff] [blame] | 1379 | if (cpuctx->task_ctx == ctx) |
| 1380 | return; |
| 1381 | |
eranian@google.com | 9b33fa6 | 2010-03-10 22:26:05 -0800 | [diff] [blame] | 1382 | perf_disable(); |
| 1383 | |
Frederic Weisbecker | 329c0e0 | 2010-01-17 12:56:05 +0100 | [diff] [blame] | 1384 | /* |
| 1385 | * We want to keep the following priority order: |
| 1386 | * cpu pinned (that don't need to move), task pinned, |
| 1387 | * cpu flexible, task flexible. |
| 1388 | */ |
| 1389 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
| 1390 | |
| 1391 | ctx_sched_in(ctx, cpuctx, EVENT_PINNED); |
| 1392 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE); |
| 1393 | ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE); |
| 1394 | |
| 1395 | cpuctx->task_ctx = ctx; |
eranian@google.com | 9b33fa6 | 2010-03-10 22:26:05 -0800 | [diff] [blame] | 1396 | |
| 1397 | perf_enable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1398 | } |
| 1399 | |
| 1400 | #define MAX_INTERRUPTS (~0ULL) |
| 1401 | |
| 1402 | static void perf_log_throttle(struct perf_event *event, int enable); |
| 1403 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1404 | static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) |
| 1405 | { |
| 1406 | u64 frequency = event->attr.sample_freq; |
| 1407 | u64 sec = NSEC_PER_SEC; |
| 1408 | u64 divisor, dividend; |
| 1409 | |
| 1410 | int count_fls, nsec_fls, frequency_fls, sec_fls; |
| 1411 | |
| 1412 | count_fls = fls64(count); |
| 1413 | nsec_fls = fls64(nsec); |
| 1414 | frequency_fls = fls64(frequency); |
| 1415 | sec_fls = 30; |
| 1416 | |
| 1417 | /* |
| 1418 | * We got @count in @nsec, with a target of sample_freq HZ |
| 1419 | * the target period becomes: |
| 1420 | * |
| 1421 | * @count * 10^9 |
| 1422 | * period = ------------------- |
| 1423 | * @nsec * sample_freq |
| 1424 | * |
| 1425 | */ |
| 1426 | |
| 1427 | /* |
| 1428 | * Reduce accuracy by one bit such that @a and @b converge |
| 1429 | * to a similar magnitude. |
| 1430 | */ |
| 1431 | #define REDUCE_FLS(a, b) \ |
| 1432 | do { \ |
| 1433 | if (a##_fls > b##_fls) { \ |
| 1434 | a >>= 1; \ |
| 1435 | a##_fls--; \ |
| 1436 | } else { \ |
| 1437 | b >>= 1; \ |
| 1438 | b##_fls--; \ |
| 1439 | } \ |
| 1440 | } while (0) |
| 1441 | |
| 1442 | /* |
| 1443 | * Reduce accuracy until either term fits in a u64, then proceed with |
| 1444 | * the other, so that finally we can do a u64/u64 division. |
| 1445 | */ |
| 1446 | while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { |
| 1447 | REDUCE_FLS(nsec, frequency); |
| 1448 | REDUCE_FLS(sec, count); |
| 1449 | } |
| 1450 | |
| 1451 | if (count_fls + sec_fls > 64) { |
| 1452 | divisor = nsec * frequency; |
| 1453 | |
| 1454 | while (count_fls + sec_fls > 64) { |
| 1455 | REDUCE_FLS(count, sec); |
| 1456 | divisor >>= 1; |
| 1457 | } |
| 1458 | |
| 1459 | dividend = count * sec; |
| 1460 | } else { |
| 1461 | dividend = count * sec; |
| 1462 | |
| 1463 | while (nsec_fls + frequency_fls > 64) { |
| 1464 | REDUCE_FLS(nsec, frequency); |
| 1465 | dividend >>= 1; |
| 1466 | } |
| 1467 | |
| 1468 | divisor = nsec * frequency; |
| 1469 | } |
| 1470 | |
| 1471 | return div64_u64(dividend, divisor); |
| 1472 | } |
| 1473 | |
Stephane Eranian | d76a081 | 2010-02-08 17:06:01 +0200 | [diff] [blame] | 1474 | static void perf_event_stop(struct perf_event *event) |
| 1475 | { |
| 1476 | if (!event->pmu->stop) |
| 1477 | return event->pmu->disable(event); |
| 1478 | |
| 1479 | return event->pmu->stop(event); |
| 1480 | } |
| 1481 | |
| 1482 | static int perf_event_start(struct perf_event *event) |
| 1483 | { |
| 1484 | if (!event->pmu->start) |
| 1485 | return event->pmu->enable(event); |
| 1486 | |
| 1487 | return event->pmu->start(event); |
| 1488 | } |
| 1489 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1490 | static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1491 | { |
| 1492 | struct hw_perf_event *hwc = &event->hw; |
| 1493 | u64 period, sample_period; |
| 1494 | s64 delta; |
| 1495 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1496 | period = perf_calculate_period(event, nsec, count); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1497 | |
| 1498 | delta = (s64)(period - hwc->sample_period); |
| 1499 | delta = (delta + 7) / 8; /* low pass filter */ |
| 1500 | |
| 1501 | sample_period = hwc->sample_period + delta; |
| 1502 | |
| 1503 | if (!sample_period) |
| 1504 | sample_period = 1; |
| 1505 | |
| 1506 | hwc->sample_period = sample_period; |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1507 | |
| 1508 | if (atomic64_read(&hwc->period_left) > 8*sample_period) { |
| 1509 | perf_disable(); |
Stephane Eranian | d76a081 | 2010-02-08 17:06:01 +0200 | [diff] [blame] | 1510 | perf_event_stop(event); |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1511 | atomic64_set(&hwc->period_left, 0); |
Stephane Eranian | d76a081 | 2010-02-08 17:06:01 +0200 | [diff] [blame] | 1512 | perf_event_start(event); |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1513 | perf_enable(); |
| 1514 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1515 | } |
| 1516 | |
| 1517 | static void perf_ctx_adjust_freq(struct perf_event_context *ctx) |
| 1518 | { |
| 1519 | struct perf_event *event; |
| 1520 | struct hw_perf_event *hwc; |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1521 | u64 interrupts, now; |
| 1522 | s64 delta; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1523 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1524 | raw_spin_lock(&ctx->lock); |
Paul Mackerras | 03541f8 | 2009-10-14 16:58:03 +1100 | [diff] [blame] | 1525 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1526 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
| 1527 | continue; |
| 1528 | |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 1529 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 1530 | continue; |
| 1531 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1532 | hwc = &event->hw; |
| 1533 | |
| 1534 | interrupts = hwc->interrupts; |
| 1535 | hwc->interrupts = 0; |
| 1536 | |
| 1537 | /* |
| 1538 | * unthrottle events on the tick |
| 1539 | */ |
| 1540 | if (interrupts == MAX_INTERRUPTS) { |
| 1541 | perf_log_throttle(event, 1); |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1542 | perf_disable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1543 | event->pmu->unthrottle(event); |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1544 | perf_enable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1545 | } |
| 1546 | |
| 1547 | if (!event->attr.freq || !event->attr.sample_freq) |
| 1548 | continue; |
| 1549 | |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1550 | perf_disable(); |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1551 | event->pmu->read(event); |
| 1552 | now = atomic64_read(&event->count); |
| 1553 | delta = now - hwc->freq_count_stamp; |
| 1554 | hwc->freq_count_stamp = now; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1555 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 1556 | if (delta > 0) |
| 1557 | perf_adjust_period(event, TICK_NSEC, delta); |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1558 | perf_enable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1559 | } |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1560 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1561 | } |
| 1562 | |
| 1563 | /* |
| 1564 | * Round-robin a context's events: |
| 1565 | */ |
| 1566 | static void rotate_ctx(struct perf_event_context *ctx) |
| 1567 | { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1568 | raw_spin_lock(&ctx->lock); |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1569 | |
Frederic Weisbecker | e286417 | 2010-01-09 21:05:28 +0100 | [diff] [blame] | 1570 | /* Rotate the first entry last of non-pinned groups */ |
Frederic Weisbecker | e286417 | 2010-01-09 21:05:28 +0100 | [diff] [blame] | 1571 | list_rotate_left(&ctx->flexible_groups); |
| 1572 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1573 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1574 | } |
| 1575 | |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1576 | void perf_event_task_tick(struct task_struct *curr) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1577 | { |
| 1578 | struct perf_cpu_context *cpuctx; |
| 1579 | struct perf_event_context *ctx; |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1580 | int rotate = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1581 | |
| 1582 | if (!atomic_read(&nr_events)) |
| 1583 | return; |
| 1584 | |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1585 | cpuctx = &__get_cpu_var(perf_cpu_context); |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1586 | if (cpuctx->ctx.nr_events && |
| 1587 | cpuctx->ctx.nr_events != cpuctx->ctx.nr_active) |
| 1588 | rotate = 1; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1589 | |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1590 | ctx = curr->perf_event_ctxp; |
| 1591 | if (ctx && ctx->nr_events && ctx->nr_events != ctx->nr_active) |
| 1592 | rotate = 1; |
Peter Zijlstra | 9717e6c | 2010-01-28 13:57:44 +0100 | [diff] [blame] | 1593 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1594 | perf_ctx_adjust_freq(&cpuctx->ctx); |
| 1595 | if (ctx) |
| 1596 | perf_ctx_adjust_freq(ctx); |
| 1597 | |
Peter Zijlstra | d4944a0 | 2010-03-08 13:51:20 +0100 | [diff] [blame] | 1598 | if (!rotate) |
| 1599 | return; |
| 1600 | |
| 1601 | perf_disable(); |
Frederic Weisbecker | 7defb0f | 2010-01-17 12:15:31 +0100 | [diff] [blame] | 1602 | cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1603 | if (ctx) |
Frederic Weisbecker | 7defb0f | 2010-01-17 12:15:31 +0100 | [diff] [blame] | 1604 | task_ctx_sched_out(ctx, EVENT_FLEXIBLE); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1605 | |
| 1606 | rotate_ctx(&cpuctx->ctx); |
| 1607 | if (ctx) |
| 1608 | rotate_ctx(ctx); |
| 1609 | |
Frederic Weisbecker | 7defb0f | 2010-01-17 12:15:31 +0100 | [diff] [blame] | 1610 | cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1611 | if (ctx) |
Frederic Weisbecker | 7defb0f | 2010-01-17 12:15:31 +0100 | [diff] [blame] | 1612 | task_ctx_sched_in(curr, EVENT_FLEXIBLE); |
Peter Zijlstra | 9717e6c | 2010-01-28 13:57:44 +0100 | [diff] [blame] | 1613 | perf_enable(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1614 | } |
| 1615 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1616 | static int event_enable_on_exec(struct perf_event *event, |
| 1617 | struct perf_event_context *ctx) |
| 1618 | { |
| 1619 | if (!event->attr.enable_on_exec) |
| 1620 | return 0; |
| 1621 | |
| 1622 | event->attr.enable_on_exec = 0; |
| 1623 | if (event->state >= PERF_EVENT_STATE_INACTIVE) |
| 1624 | return 0; |
| 1625 | |
| 1626 | __perf_event_mark_enabled(event, ctx); |
| 1627 | |
| 1628 | return 1; |
| 1629 | } |
| 1630 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1631 | /* |
| 1632 | * Enable all of a task's events that have been marked enable-on-exec. |
| 1633 | * This expects task == current. |
| 1634 | */ |
| 1635 | static void perf_event_enable_on_exec(struct task_struct *task) |
| 1636 | { |
| 1637 | struct perf_event_context *ctx; |
| 1638 | struct perf_event *event; |
| 1639 | unsigned long flags; |
| 1640 | int enabled = 0; |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1641 | int ret; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1642 | |
| 1643 | local_irq_save(flags); |
| 1644 | ctx = task->perf_event_ctxp; |
| 1645 | if (!ctx || !ctx->nr_events) |
| 1646 | goto out; |
| 1647 | |
| 1648 | __perf_event_task_sched_out(ctx); |
| 1649 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1650 | raw_spin_lock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1651 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1652 | list_for_each_entry(event, &ctx->pinned_groups, group_entry) { |
| 1653 | ret = event_enable_on_exec(event, ctx); |
| 1654 | if (ret) |
| 1655 | enabled = 1; |
| 1656 | } |
| 1657 | |
| 1658 | list_for_each_entry(event, &ctx->flexible_groups, group_entry) { |
| 1659 | ret = event_enable_on_exec(event, ctx); |
| 1660 | if (ret) |
| 1661 | enabled = 1; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1662 | } |
| 1663 | |
| 1664 | /* |
| 1665 | * Unclone this context if we enabled any event. |
| 1666 | */ |
| 1667 | if (enabled) |
| 1668 | unclone_ctx(ctx); |
| 1669 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1670 | raw_spin_unlock(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1671 | |
Peter Zijlstra | 49f4743 | 2009-12-27 11:51:52 +0100 | [diff] [blame] | 1672 | perf_event_task_sched_in(task); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1673 | out: |
| 1674 | local_irq_restore(flags); |
| 1675 | } |
| 1676 | |
| 1677 | /* |
| 1678 | * Cross CPU call to read the hardware event |
| 1679 | */ |
| 1680 | static void __perf_event_read(void *info) |
| 1681 | { |
| 1682 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 1683 | struct perf_event *event = info; |
| 1684 | struct perf_event_context *ctx = event->ctx; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1685 | |
| 1686 | /* |
| 1687 | * If this is a task context, we need to check whether it is |
| 1688 | * the current task context of this cpu. If not it has been |
| 1689 | * scheduled out before the smp call arrived. In that case |
| 1690 | * event->count would have been updated to a recent sample |
| 1691 | * when the event was scheduled out. |
| 1692 | */ |
| 1693 | if (ctx->task && cpuctx->task_ctx != ctx) |
| 1694 | return; |
| 1695 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1696 | raw_spin_lock(&ctx->lock); |
Peter Zijlstra | 58e5ad1 | 2009-11-20 22:19:53 +0100 | [diff] [blame] | 1697 | update_context_time(ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1698 | update_event_times(event); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1699 | raw_spin_unlock(&ctx->lock); |
Peter Zijlstra | 2b8988c | 2009-11-20 22:19:54 +0100 | [diff] [blame] | 1700 | |
Peter Zijlstra | 58e5ad1 | 2009-11-20 22:19:53 +0100 | [diff] [blame] | 1701 | event->pmu->read(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1702 | } |
| 1703 | |
| 1704 | static u64 perf_event_read(struct perf_event *event) |
| 1705 | { |
| 1706 | /* |
| 1707 | * If event is enabled and currently active on a CPU, update the |
| 1708 | * value in the event structure: |
| 1709 | */ |
| 1710 | if (event->state == PERF_EVENT_STATE_ACTIVE) { |
| 1711 | smp_call_function_single(event->oncpu, |
| 1712 | __perf_event_read, event, 1); |
| 1713 | } else if (event->state == PERF_EVENT_STATE_INACTIVE) { |
Peter Zijlstra | 2b8988c | 2009-11-20 22:19:54 +0100 | [diff] [blame] | 1714 | struct perf_event_context *ctx = event->ctx; |
| 1715 | unsigned long flags; |
| 1716 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1717 | raw_spin_lock_irqsave(&ctx->lock, flags); |
Peter Zijlstra | 2b8988c | 2009-11-20 22:19:54 +0100 | [diff] [blame] | 1718 | update_context_time(ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1719 | update_event_times(event); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1720 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1721 | } |
| 1722 | |
| 1723 | return atomic64_read(&event->count); |
| 1724 | } |
| 1725 | |
| 1726 | /* |
| 1727 | * Initialize the perf_event context in a task_struct: |
| 1728 | */ |
| 1729 | static void |
| 1730 | __perf_event_init_context(struct perf_event_context *ctx, |
| 1731 | struct task_struct *task) |
| 1732 | { |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1733 | raw_spin_lock_init(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1734 | mutex_init(&ctx->mutex); |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 1735 | INIT_LIST_HEAD(&ctx->pinned_groups); |
| 1736 | INIT_LIST_HEAD(&ctx->flexible_groups); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1737 | INIT_LIST_HEAD(&ctx->event_list); |
| 1738 | atomic_set(&ctx->refcount, 1); |
| 1739 | ctx->task = task; |
| 1740 | } |
| 1741 | |
| 1742 | static struct perf_event_context *find_get_context(pid_t pid, int cpu) |
| 1743 | { |
| 1744 | struct perf_event_context *ctx; |
| 1745 | struct perf_cpu_context *cpuctx; |
| 1746 | struct task_struct *task; |
| 1747 | unsigned long flags; |
| 1748 | int err; |
| 1749 | |
Peter Zijlstra | f4c4176 | 2009-12-16 17:55:54 +0100 | [diff] [blame] | 1750 | if (pid == -1 && cpu != -1) { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1751 | /* Must be root to operate on a CPU event: */ |
| 1752 | if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) |
| 1753 | return ERR_PTR(-EACCES); |
| 1754 | |
Paul Mackerras | 0f624e7 | 2009-12-15 19:40:32 +1100 | [diff] [blame] | 1755 | if (cpu < 0 || cpu >= nr_cpumask_bits) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1756 | return ERR_PTR(-EINVAL); |
| 1757 | |
| 1758 | /* |
| 1759 | * We could be clever and allow to attach a event to an |
| 1760 | * offline CPU and activate it when the CPU comes up, but |
| 1761 | * that's for later. |
| 1762 | */ |
Rusty Russell | f6325e3 | 2009-12-17 11:43:08 -0600 | [diff] [blame] | 1763 | if (!cpu_online(cpu)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1764 | return ERR_PTR(-ENODEV); |
| 1765 | |
| 1766 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 1767 | ctx = &cpuctx->ctx; |
| 1768 | get_ctx(ctx); |
| 1769 | |
| 1770 | return ctx; |
| 1771 | } |
| 1772 | |
| 1773 | rcu_read_lock(); |
| 1774 | if (!pid) |
| 1775 | task = current; |
| 1776 | else |
| 1777 | task = find_task_by_vpid(pid); |
| 1778 | if (task) |
| 1779 | get_task_struct(task); |
| 1780 | rcu_read_unlock(); |
| 1781 | |
| 1782 | if (!task) |
| 1783 | return ERR_PTR(-ESRCH); |
| 1784 | |
| 1785 | /* |
| 1786 | * Can't attach events to a dying task. |
| 1787 | */ |
| 1788 | err = -ESRCH; |
| 1789 | if (task->flags & PF_EXITING) |
| 1790 | goto errout; |
| 1791 | |
| 1792 | /* Reuse ptrace permission checks for now. */ |
| 1793 | err = -EACCES; |
| 1794 | if (!ptrace_may_access(task, PTRACE_MODE_READ)) |
| 1795 | goto errout; |
| 1796 | |
| 1797 | retry: |
| 1798 | ctx = perf_lock_task_context(task, &flags); |
| 1799 | if (ctx) { |
| 1800 | unclone_ctx(ctx); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 1801 | raw_spin_unlock_irqrestore(&ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1802 | } |
| 1803 | |
| 1804 | if (!ctx) { |
Xiao Guangrong | aa5452d | 2009-12-09 11:28:13 +0800 | [diff] [blame] | 1805 | ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1806 | err = -ENOMEM; |
| 1807 | if (!ctx) |
| 1808 | goto errout; |
| 1809 | __perf_event_init_context(ctx, task); |
| 1810 | get_ctx(ctx); |
| 1811 | if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) { |
| 1812 | /* |
| 1813 | * We raced with some other task; use |
| 1814 | * the context they set. |
| 1815 | */ |
| 1816 | kfree(ctx); |
| 1817 | goto retry; |
| 1818 | } |
| 1819 | get_task_struct(task); |
| 1820 | } |
| 1821 | |
| 1822 | put_task_struct(task); |
| 1823 | return ctx; |
| 1824 | |
| 1825 | errout: |
| 1826 | put_task_struct(task); |
| 1827 | return ERR_PTR(err); |
| 1828 | } |
| 1829 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 1830 | static void perf_event_free_filter(struct perf_event *event); |
| 1831 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1832 | static void free_event_rcu(struct rcu_head *head) |
| 1833 | { |
| 1834 | struct perf_event *event; |
| 1835 | |
| 1836 | event = container_of(head, struct perf_event, rcu_head); |
| 1837 | if (event->ns) |
| 1838 | put_pid_ns(event->ns); |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 1839 | perf_event_free_filter(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1840 | kfree(event); |
| 1841 | } |
| 1842 | |
| 1843 | static void perf_pending_sync(struct perf_event *event); |
| 1844 | |
| 1845 | static void free_event(struct perf_event *event) |
| 1846 | { |
| 1847 | perf_pending_sync(event); |
| 1848 | |
| 1849 | if (!event->parent) { |
| 1850 | atomic_dec(&nr_events); |
| 1851 | if (event->attr.mmap) |
| 1852 | atomic_dec(&nr_mmap_events); |
| 1853 | if (event->attr.comm) |
| 1854 | atomic_dec(&nr_comm_events); |
| 1855 | if (event->attr.task) |
| 1856 | atomic_dec(&nr_task_events); |
| 1857 | } |
| 1858 | |
| 1859 | if (event->output) { |
| 1860 | fput(event->output->filp); |
| 1861 | event->output = NULL; |
| 1862 | } |
| 1863 | |
| 1864 | if (event->destroy) |
| 1865 | event->destroy(event); |
| 1866 | |
| 1867 | put_ctx(event->ctx); |
| 1868 | call_rcu(&event->rcu_head, free_event_rcu); |
| 1869 | } |
| 1870 | |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 1871 | int perf_event_release_kernel(struct perf_event *event) |
| 1872 | { |
| 1873 | struct perf_event_context *ctx = event->ctx; |
| 1874 | |
Peter Zijlstra | 050735b | 2010-05-11 11:51:53 +0200 | [diff] [blame] | 1875 | /* |
| 1876 | * Remove from the PMU, can't get re-enabled since we got |
| 1877 | * here because the last ref went. |
| 1878 | */ |
| 1879 | perf_event_disable(event); |
| 1880 | |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 1881 | WARN_ON_ONCE(ctx->parent_ctx); |
Peter Zijlstra | a0507c8 | 2010-05-06 15:42:53 +0200 | [diff] [blame] | 1882 | /* |
| 1883 | * There are two ways this annotation is useful: |
| 1884 | * |
| 1885 | * 1) there is a lock recursion from perf_event_exit_task |
| 1886 | * see the comment there. |
| 1887 | * |
| 1888 | * 2) there is a lock-inversion with mmap_sem through |
| 1889 | * perf_event_read_group(), which takes faults while |
| 1890 | * holding ctx->mutex, however this is called after |
| 1891 | * the last filedesc died, so there is no possibility |
| 1892 | * to trigger the AB-BA case. |
| 1893 | */ |
| 1894 | mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); |
Peter Zijlstra | 050735b | 2010-05-11 11:51:53 +0200 | [diff] [blame] | 1895 | raw_spin_lock_irq(&ctx->lock); |
| 1896 | list_del_event(event, ctx); |
| 1897 | perf_destroy_group(event, ctx); |
| 1898 | raw_spin_unlock_irq(&ctx->lock); |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 1899 | mutex_unlock(&ctx->mutex); |
| 1900 | |
| 1901 | mutex_lock(&event->owner->perf_event_mutex); |
| 1902 | list_del_init(&event->owner_entry); |
| 1903 | mutex_unlock(&event->owner->perf_event_mutex); |
| 1904 | put_task_struct(event->owner); |
| 1905 | |
| 1906 | free_event(event); |
| 1907 | |
| 1908 | return 0; |
| 1909 | } |
| 1910 | EXPORT_SYMBOL_GPL(perf_event_release_kernel); |
| 1911 | |
Peter Zijlstra | a66a305 | 2009-11-23 11:37:23 +0100 | [diff] [blame] | 1912 | /* |
| 1913 | * Called when the last reference to the file is gone. |
| 1914 | */ |
| 1915 | static int perf_release(struct inode *inode, struct file *file) |
| 1916 | { |
| 1917 | struct perf_event *event = file->private_data; |
| 1918 | |
| 1919 | file->private_data = NULL; |
| 1920 | |
| 1921 | return perf_event_release_kernel(event); |
| 1922 | } |
| 1923 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1924 | static int perf_event_read_size(struct perf_event *event) |
| 1925 | { |
| 1926 | int entry = sizeof(u64); /* value */ |
| 1927 | int size = 0; |
| 1928 | int nr = 1; |
| 1929 | |
| 1930 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
| 1931 | size += sizeof(u64); |
| 1932 | |
| 1933 | if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) |
| 1934 | size += sizeof(u64); |
| 1935 | |
| 1936 | if (event->attr.read_format & PERF_FORMAT_ID) |
| 1937 | entry += sizeof(u64); |
| 1938 | |
| 1939 | if (event->attr.read_format & PERF_FORMAT_GROUP) { |
| 1940 | nr += event->group_leader->nr_siblings; |
| 1941 | size += sizeof(u64); |
| 1942 | } |
| 1943 | |
| 1944 | size += entry * nr; |
| 1945 | |
| 1946 | return size; |
| 1947 | } |
| 1948 | |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1949 | u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1950 | { |
| 1951 | struct perf_event *child; |
| 1952 | u64 total = 0; |
| 1953 | |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1954 | *enabled = 0; |
| 1955 | *running = 0; |
| 1956 | |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 1957 | mutex_lock(&event->child_mutex); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1958 | total += perf_event_read(event); |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1959 | *enabled += event->total_time_enabled + |
| 1960 | atomic64_read(&event->child_total_time_enabled); |
| 1961 | *running += event->total_time_running + |
| 1962 | atomic64_read(&event->child_total_time_running); |
| 1963 | |
| 1964 | list_for_each_entry(child, &event->child_list, child_list) { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1965 | total += perf_event_read(child); |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1966 | *enabled += child->total_time_enabled; |
| 1967 | *running += child->total_time_running; |
| 1968 | } |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 1969 | mutex_unlock(&event->child_mutex); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1970 | |
| 1971 | return total; |
| 1972 | } |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 1973 | EXPORT_SYMBOL_GPL(perf_event_read_value); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1974 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1975 | static int perf_event_read_group(struct perf_event *event, |
| 1976 | u64 read_format, char __user *buf) |
| 1977 | { |
| 1978 | struct perf_event *leader = event->group_leader, *sub; |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 1979 | int n = 0, size = 0, ret = -EFAULT; |
| 1980 | struct perf_event_context *ctx = leader->ctx; |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 1981 | u64 values[5]; |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1982 | u64 count, enabled, running; |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 1983 | |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 1984 | mutex_lock(&ctx->mutex); |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1985 | count = perf_event_read_value(leader, &enabled, &running); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1986 | |
| 1987 | values[n++] = 1 + leader->nr_siblings; |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 1988 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
| 1989 | values[n++] = enabled; |
| 1990 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) |
| 1991 | values[n++] = running; |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 1992 | values[n++] = count; |
| 1993 | if (read_format & PERF_FORMAT_ID) |
| 1994 | values[n++] = primary_event_id(leader); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1995 | |
| 1996 | size = n * sizeof(u64); |
| 1997 | |
| 1998 | if (copy_to_user(buf, values, size)) |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 1999 | goto unlock; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2000 | |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 2001 | ret = size; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2002 | |
| 2003 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 2004 | n = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2005 | |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 2006 | values[n++] = perf_event_read_value(sub, &enabled, &running); |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 2007 | if (read_format & PERF_FORMAT_ID) |
| 2008 | values[n++] = primary_event_id(sub); |
| 2009 | |
| 2010 | size = n * sizeof(u64); |
| 2011 | |
Stephane Eranian | 184d3da | 2009-11-23 21:40:49 -0800 | [diff] [blame] | 2012 | if (copy_to_user(buf + ret, values, size)) { |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 2013 | ret = -EFAULT; |
| 2014 | goto unlock; |
| 2015 | } |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 2016 | |
| 2017 | ret += size; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2018 | } |
Peter Zijlstra | 6f10581 | 2009-11-20 22:19:56 +0100 | [diff] [blame] | 2019 | unlock: |
| 2020 | mutex_unlock(&ctx->mutex); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2021 | |
Peter Zijlstra | abf4868 | 2009-11-20 22:19:49 +0100 | [diff] [blame] | 2022 | return ret; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2023 | } |
| 2024 | |
| 2025 | static int perf_event_read_one(struct perf_event *event, |
| 2026 | u64 read_format, char __user *buf) |
| 2027 | { |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 2028 | u64 enabled, running; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2029 | u64 values[4]; |
| 2030 | int n = 0; |
| 2031 | |
Peter Zijlstra | 59ed446 | 2009-11-20 22:19:55 +0100 | [diff] [blame] | 2032 | values[n++] = perf_event_read_value(event, &enabled, &running); |
| 2033 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
| 2034 | values[n++] = enabled; |
| 2035 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) |
| 2036 | values[n++] = running; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2037 | if (read_format & PERF_FORMAT_ID) |
| 2038 | values[n++] = primary_event_id(event); |
| 2039 | |
| 2040 | if (copy_to_user(buf, values, n * sizeof(u64))) |
| 2041 | return -EFAULT; |
| 2042 | |
| 2043 | return n * sizeof(u64); |
| 2044 | } |
| 2045 | |
| 2046 | /* |
| 2047 | * Read the performance event - simple non blocking version for now |
| 2048 | */ |
| 2049 | static ssize_t |
| 2050 | perf_read_hw(struct perf_event *event, char __user *buf, size_t count) |
| 2051 | { |
| 2052 | u64 read_format = event->attr.read_format; |
| 2053 | int ret; |
| 2054 | |
| 2055 | /* |
| 2056 | * Return end-of-file for a read on a event that is in |
| 2057 | * error state (i.e. because it was pinned but it couldn't be |
| 2058 | * scheduled on to the CPU at some point). |
| 2059 | */ |
| 2060 | if (event->state == PERF_EVENT_STATE_ERROR) |
| 2061 | return 0; |
| 2062 | |
| 2063 | if (count < perf_event_read_size(event)) |
| 2064 | return -ENOSPC; |
| 2065 | |
| 2066 | WARN_ON_ONCE(event->ctx->parent_ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2067 | if (read_format & PERF_FORMAT_GROUP) |
| 2068 | ret = perf_event_read_group(event, read_format, buf); |
| 2069 | else |
| 2070 | ret = perf_event_read_one(event, read_format, buf); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2071 | |
| 2072 | return ret; |
| 2073 | } |
| 2074 | |
| 2075 | static ssize_t |
| 2076 | perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 2077 | { |
| 2078 | struct perf_event *event = file->private_data; |
| 2079 | |
| 2080 | return perf_read_hw(event, buf, count); |
| 2081 | } |
| 2082 | |
| 2083 | static unsigned int perf_poll(struct file *file, poll_table *wait) |
| 2084 | { |
| 2085 | struct perf_event *event = file->private_data; |
| 2086 | struct perf_mmap_data *data; |
| 2087 | unsigned int events = POLL_HUP; |
| 2088 | |
| 2089 | rcu_read_lock(); |
| 2090 | data = rcu_dereference(event->data); |
| 2091 | if (data) |
| 2092 | events = atomic_xchg(&data->poll, 0); |
| 2093 | rcu_read_unlock(); |
| 2094 | |
| 2095 | poll_wait(file, &event->waitq, wait); |
| 2096 | |
| 2097 | return events; |
| 2098 | } |
| 2099 | |
| 2100 | static void perf_event_reset(struct perf_event *event) |
| 2101 | { |
| 2102 | (void)perf_event_read(event); |
| 2103 | atomic64_set(&event->count, 0); |
| 2104 | perf_event_update_userpage(event); |
| 2105 | } |
| 2106 | |
| 2107 | /* |
| 2108 | * Holding the top-level event's child_mutex means that any |
| 2109 | * descendant process that has inherited this event will block |
| 2110 | * in sync_child_event if it goes to exit, thus satisfying the |
| 2111 | * task existence requirements of perf_event_enable/disable. |
| 2112 | */ |
| 2113 | static void perf_event_for_each_child(struct perf_event *event, |
| 2114 | void (*func)(struct perf_event *)) |
| 2115 | { |
| 2116 | struct perf_event *child; |
| 2117 | |
| 2118 | WARN_ON_ONCE(event->ctx->parent_ctx); |
| 2119 | mutex_lock(&event->child_mutex); |
| 2120 | func(event); |
| 2121 | list_for_each_entry(child, &event->child_list, child_list) |
| 2122 | func(child); |
| 2123 | mutex_unlock(&event->child_mutex); |
| 2124 | } |
| 2125 | |
| 2126 | static void perf_event_for_each(struct perf_event *event, |
| 2127 | void (*func)(struct perf_event *)) |
| 2128 | { |
| 2129 | struct perf_event_context *ctx = event->ctx; |
| 2130 | struct perf_event *sibling; |
| 2131 | |
| 2132 | WARN_ON_ONCE(ctx->parent_ctx); |
| 2133 | mutex_lock(&ctx->mutex); |
| 2134 | event = event->group_leader; |
| 2135 | |
| 2136 | perf_event_for_each_child(event, func); |
| 2137 | func(event); |
| 2138 | list_for_each_entry(sibling, &event->sibling_list, group_entry) |
| 2139 | perf_event_for_each_child(event, func); |
| 2140 | mutex_unlock(&ctx->mutex); |
| 2141 | } |
| 2142 | |
| 2143 | static int perf_event_period(struct perf_event *event, u64 __user *arg) |
| 2144 | { |
| 2145 | struct perf_event_context *ctx = event->ctx; |
| 2146 | unsigned long size; |
| 2147 | int ret = 0; |
| 2148 | u64 value; |
| 2149 | |
| 2150 | if (!event->attr.sample_period) |
| 2151 | return -EINVAL; |
| 2152 | |
| 2153 | size = copy_from_user(&value, arg, sizeof(value)); |
| 2154 | if (size != sizeof(value)) |
| 2155 | return -EFAULT; |
| 2156 | |
| 2157 | if (!value) |
| 2158 | return -EINVAL; |
| 2159 | |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 2160 | raw_spin_lock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2161 | if (event->attr.freq) { |
| 2162 | if (value > sysctl_perf_event_sample_rate) { |
| 2163 | ret = -EINVAL; |
| 2164 | goto unlock; |
| 2165 | } |
| 2166 | |
| 2167 | event->attr.sample_freq = value; |
| 2168 | } else { |
| 2169 | event->attr.sample_period = value; |
| 2170 | event->hw.sample_period = value; |
| 2171 | } |
| 2172 | unlock: |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 2173 | raw_spin_unlock_irq(&ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2174 | |
| 2175 | return ret; |
| 2176 | } |
| 2177 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 2178 | static int perf_event_set_output(struct perf_event *event, int output_fd); |
| 2179 | static int perf_event_set_filter(struct perf_event *event, void __user *arg); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2180 | |
| 2181 | static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 2182 | { |
| 2183 | struct perf_event *event = file->private_data; |
| 2184 | void (*func)(struct perf_event *); |
| 2185 | u32 flags = arg; |
| 2186 | |
| 2187 | switch (cmd) { |
| 2188 | case PERF_EVENT_IOC_ENABLE: |
| 2189 | func = perf_event_enable; |
| 2190 | break; |
| 2191 | case PERF_EVENT_IOC_DISABLE: |
| 2192 | func = perf_event_disable; |
| 2193 | break; |
| 2194 | case PERF_EVENT_IOC_RESET: |
| 2195 | func = perf_event_reset; |
| 2196 | break; |
| 2197 | |
| 2198 | case PERF_EVENT_IOC_REFRESH: |
| 2199 | return perf_event_refresh(event, arg); |
| 2200 | |
| 2201 | case PERF_EVENT_IOC_PERIOD: |
| 2202 | return perf_event_period(event, (u64 __user *)arg); |
| 2203 | |
| 2204 | case PERF_EVENT_IOC_SET_OUTPUT: |
| 2205 | return perf_event_set_output(event, arg); |
| 2206 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 2207 | case PERF_EVENT_IOC_SET_FILTER: |
| 2208 | return perf_event_set_filter(event, (void __user *)arg); |
| 2209 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2210 | default: |
| 2211 | return -ENOTTY; |
| 2212 | } |
| 2213 | |
| 2214 | if (flags & PERF_IOC_FLAG_GROUP) |
| 2215 | perf_event_for_each(event, func); |
| 2216 | else |
| 2217 | perf_event_for_each_child(event, func); |
| 2218 | |
| 2219 | return 0; |
| 2220 | } |
| 2221 | |
| 2222 | int perf_event_task_enable(void) |
| 2223 | { |
| 2224 | struct perf_event *event; |
| 2225 | |
| 2226 | mutex_lock(¤t->perf_event_mutex); |
| 2227 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) |
| 2228 | perf_event_for_each_child(event, perf_event_enable); |
| 2229 | mutex_unlock(¤t->perf_event_mutex); |
| 2230 | |
| 2231 | return 0; |
| 2232 | } |
| 2233 | |
| 2234 | int perf_event_task_disable(void) |
| 2235 | { |
| 2236 | struct perf_event *event; |
| 2237 | |
| 2238 | mutex_lock(¤t->perf_event_mutex); |
| 2239 | list_for_each_entry(event, ¤t->perf_event_list, owner_entry) |
| 2240 | perf_event_for_each_child(event, perf_event_disable); |
| 2241 | mutex_unlock(¤t->perf_event_mutex); |
| 2242 | |
| 2243 | return 0; |
| 2244 | } |
| 2245 | |
| 2246 | #ifndef PERF_EVENT_INDEX_OFFSET |
| 2247 | # define PERF_EVENT_INDEX_OFFSET 0 |
| 2248 | #endif |
| 2249 | |
| 2250 | static int perf_event_index(struct perf_event *event) |
| 2251 | { |
| 2252 | if (event->state != PERF_EVENT_STATE_ACTIVE) |
| 2253 | return 0; |
| 2254 | |
| 2255 | return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET; |
| 2256 | } |
| 2257 | |
| 2258 | /* |
| 2259 | * Callers need to ensure there can be no nesting of this function, otherwise |
| 2260 | * the seqlock logic goes bad. We can not serialize this because the arch |
| 2261 | * code calls this from NMI context. |
| 2262 | */ |
| 2263 | void perf_event_update_userpage(struct perf_event *event) |
| 2264 | { |
| 2265 | struct perf_event_mmap_page *userpg; |
| 2266 | struct perf_mmap_data *data; |
| 2267 | |
| 2268 | rcu_read_lock(); |
| 2269 | data = rcu_dereference(event->data); |
| 2270 | if (!data) |
| 2271 | goto unlock; |
| 2272 | |
| 2273 | userpg = data->user_page; |
| 2274 | |
| 2275 | /* |
| 2276 | * Disable preemption so as to not let the corresponding user-space |
| 2277 | * spin too long if we get preempted. |
| 2278 | */ |
| 2279 | preempt_disable(); |
| 2280 | ++userpg->lock; |
| 2281 | barrier(); |
| 2282 | userpg->index = perf_event_index(event); |
| 2283 | userpg->offset = atomic64_read(&event->count); |
| 2284 | if (event->state == PERF_EVENT_STATE_ACTIVE) |
| 2285 | userpg->offset -= atomic64_read(&event->hw.prev_count); |
| 2286 | |
| 2287 | userpg->time_enabled = event->total_time_enabled + |
| 2288 | atomic64_read(&event->child_total_time_enabled); |
| 2289 | |
| 2290 | userpg->time_running = event->total_time_running + |
| 2291 | atomic64_read(&event->child_total_time_running); |
| 2292 | |
| 2293 | barrier(); |
| 2294 | ++userpg->lock; |
| 2295 | preempt_enable(); |
| 2296 | unlock: |
| 2297 | rcu_read_unlock(); |
| 2298 | } |
| 2299 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2300 | static unsigned long perf_data_size(struct perf_mmap_data *data) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2301 | { |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2302 | return data->nr_pages << (PAGE_SHIFT + data->data_order); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2303 | } |
| 2304 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2305 | #ifndef CONFIG_PERF_USE_VMALLOC |
| 2306 | |
| 2307 | /* |
| 2308 | * Back perf_mmap() with regular GFP_KERNEL-0 pages. |
| 2309 | */ |
| 2310 | |
| 2311 | static struct page * |
| 2312 | perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff) |
| 2313 | { |
| 2314 | if (pgoff > data->nr_pages) |
| 2315 | return NULL; |
| 2316 | |
| 2317 | if (pgoff == 0) |
| 2318 | return virt_to_page(data->user_page); |
| 2319 | |
| 2320 | return virt_to_page(data->data_pages[pgoff - 1]); |
| 2321 | } |
| 2322 | |
| 2323 | static struct perf_mmap_data * |
| 2324 | perf_mmap_data_alloc(struct perf_event *event, int nr_pages) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2325 | { |
| 2326 | struct perf_mmap_data *data; |
| 2327 | unsigned long size; |
| 2328 | int i; |
| 2329 | |
| 2330 | WARN_ON(atomic_read(&event->mmap_count)); |
| 2331 | |
| 2332 | size = sizeof(struct perf_mmap_data); |
| 2333 | size += nr_pages * sizeof(void *); |
| 2334 | |
| 2335 | data = kzalloc(size, GFP_KERNEL); |
| 2336 | if (!data) |
| 2337 | goto fail; |
| 2338 | |
| 2339 | data->user_page = (void *)get_zeroed_page(GFP_KERNEL); |
| 2340 | if (!data->user_page) |
| 2341 | goto fail_user_page; |
| 2342 | |
| 2343 | for (i = 0; i < nr_pages; i++) { |
| 2344 | data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); |
| 2345 | if (!data->data_pages[i]) |
| 2346 | goto fail_data_pages; |
| 2347 | } |
| 2348 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2349 | data->data_order = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2350 | data->nr_pages = nr_pages; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2351 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2352 | return data; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2353 | |
| 2354 | fail_data_pages: |
| 2355 | for (i--; i >= 0; i--) |
| 2356 | free_page((unsigned long)data->data_pages[i]); |
| 2357 | |
| 2358 | free_page((unsigned long)data->user_page); |
| 2359 | |
| 2360 | fail_user_page: |
| 2361 | kfree(data); |
| 2362 | |
| 2363 | fail: |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2364 | return NULL; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2365 | } |
| 2366 | |
| 2367 | static void perf_mmap_free_page(unsigned long addr) |
| 2368 | { |
| 2369 | struct page *page = virt_to_page((void *)addr); |
| 2370 | |
| 2371 | page->mapping = NULL; |
| 2372 | __free_page(page); |
| 2373 | } |
| 2374 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2375 | static void perf_mmap_data_free(struct perf_mmap_data *data) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2376 | { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2377 | int i; |
| 2378 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2379 | perf_mmap_free_page((unsigned long)data->user_page); |
| 2380 | for (i = 0; i < data->nr_pages; i++) |
| 2381 | perf_mmap_free_page((unsigned long)data->data_pages[i]); |
Kristian Høgsberg | ec70ccd | 2009-12-01 15:05:01 -0500 | [diff] [blame] | 2382 | kfree(data); |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2383 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2384 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2385 | #else |
| 2386 | |
| 2387 | /* |
| 2388 | * Back perf_mmap() with vmalloc memory. |
| 2389 | * |
| 2390 | * Required for architectures that have d-cache aliasing issues. |
| 2391 | */ |
| 2392 | |
| 2393 | static struct page * |
| 2394 | perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff) |
| 2395 | { |
| 2396 | if (pgoff > (1UL << data->data_order)) |
| 2397 | return NULL; |
| 2398 | |
| 2399 | return vmalloc_to_page((void *)data->user_page + pgoff * PAGE_SIZE); |
| 2400 | } |
| 2401 | |
| 2402 | static void perf_mmap_unmark_page(void *addr) |
| 2403 | { |
| 2404 | struct page *page = vmalloc_to_page(addr); |
| 2405 | |
| 2406 | page->mapping = NULL; |
| 2407 | } |
| 2408 | |
| 2409 | static void perf_mmap_data_free_work(struct work_struct *work) |
| 2410 | { |
| 2411 | struct perf_mmap_data *data; |
| 2412 | void *base; |
| 2413 | int i, nr; |
| 2414 | |
| 2415 | data = container_of(work, struct perf_mmap_data, work); |
| 2416 | nr = 1 << data->data_order; |
| 2417 | |
| 2418 | base = data->user_page; |
| 2419 | for (i = 0; i < nr + 1; i++) |
| 2420 | perf_mmap_unmark_page(base + (i * PAGE_SIZE)); |
| 2421 | |
| 2422 | vfree(base); |
Kristian Høgsberg | ec70ccd | 2009-12-01 15:05:01 -0500 | [diff] [blame] | 2423 | kfree(data); |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2424 | } |
| 2425 | |
| 2426 | static void perf_mmap_data_free(struct perf_mmap_data *data) |
| 2427 | { |
| 2428 | schedule_work(&data->work); |
| 2429 | } |
| 2430 | |
| 2431 | static struct perf_mmap_data * |
| 2432 | perf_mmap_data_alloc(struct perf_event *event, int nr_pages) |
| 2433 | { |
| 2434 | struct perf_mmap_data *data; |
| 2435 | unsigned long size; |
| 2436 | void *all_buf; |
| 2437 | |
| 2438 | WARN_ON(atomic_read(&event->mmap_count)); |
| 2439 | |
| 2440 | size = sizeof(struct perf_mmap_data); |
| 2441 | size += sizeof(void *); |
| 2442 | |
| 2443 | data = kzalloc(size, GFP_KERNEL); |
| 2444 | if (!data) |
| 2445 | goto fail; |
| 2446 | |
| 2447 | INIT_WORK(&data->work, perf_mmap_data_free_work); |
| 2448 | |
| 2449 | all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE); |
| 2450 | if (!all_buf) |
| 2451 | goto fail_all_buf; |
| 2452 | |
| 2453 | data->user_page = all_buf; |
| 2454 | data->data_pages[0] = all_buf + PAGE_SIZE; |
| 2455 | data->data_order = ilog2(nr_pages); |
| 2456 | data->nr_pages = 1; |
| 2457 | |
| 2458 | return data; |
| 2459 | |
| 2460 | fail_all_buf: |
| 2461 | kfree(data); |
| 2462 | |
| 2463 | fail: |
| 2464 | return NULL; |
| 2465 | } |
| 2466 | |
| 2467 | #endif |
| 2468 | |
| 2469 | static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 2470 | { |
| 2471 | struct perf_event *event = vma->vm_file->private_data; |
| 2472 | struct perf_mmap_data *data; |
| 2473 | int ret = VM_FAULT_SIGBUS; |
| 2474 | |
| 2475 | if (vmf->flags & FAULT_FLAG_MKWRITE) { |
| 2476 | if (vmf->pgoff == 0) |
| 2477 | ret = 0; |
| 2478 | return ret; |
| 2479 | } |
| 2480 | |
| 2481 | rcu_read_lock(); |
| 2482 | data = rcu_dereference(event->data); |
| 2483 | if (!data) |
| 2484 | goto unlock; |
| 2485 | |
| 2486 | if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE)) |
| 2487 | goto unlock; |
| 2488 | |
| 2489 | vmf->page = perf_mmap_to_page(data, vmf->pgoff); |
| 2490 | if (!vmf->page) |
| 2491 | goto unlock; |
| 2492 | |
| 2493 | get_page(vmf->page); |
| 2494 | vmf->page->mapping = vma->vm_file->f_mapping; |
| 2495 | vmf->page->index = vmf->pgoff; |
| 2496 | |
| 2497 | ret = 0; |
| 2498 | unlock: |
| 2499 | rcu_read_unlock(); |
| 2500 | |
| 2501 | return ret; |
| 2502 | } |
| 2503 | |
| 2504 | static void |
| 2505 | perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data) |
| 2506 | { |
| 2507 | long max_size = perf_data_size(data); |
| 2508 | |
| 2509 | atomic_set(&data->lock, -1); |
| 2510 | |
| 2511 | if (event->attr.watermark) { |
| 2512 | data->watermark = min_t(long, max_size, |
| 2513 | event->attr.wakeup_watermark); |
| 2514 | } |
| 2515 | |
| 2516 | if (!data->watermark) |
Stephane Eranian | 8904b18 | 2009-11-20 22:19:57 +0100 | [diff] [blame] | 2517 | data->watermark = max_size / 2; |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2518 | |
| 2519 | |
| 2520 | rcu_assign_pointer(event->data, data); |
| 2521 | } |
| 2522 | |
| 2523 | static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head) |
| 2524 | { |
| 2525 | struct perf_mmap_data *data; |
| 2526 | |
| 2527 | data = container_of(rcu_head, struct perf_mmap_data, rcu_head); |
| 2528 | perf_mmap_data_free(data); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2529 | } |
| 2530 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2531 | static void perf_mmap_data_release(struct perf_event *event) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2532 | { |
| 2533 | struct perf_mmap_data *data = event->data; |
| 2534 | |
| 2535 | WARN_ON(atomic_read(&event->mmap_count)); |
| 2536 | |
| 2537 | rcu_assign_pointer(event->data, NULL); |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2538 | call_rcu(&data->rcu_head, perf_mmap_data_free_rcu); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2539 | } |
| 2540 | |
| 2541 | static void perf_mmap_open(struct vm_area_struct *vma) |
| 2542 | { |
| 2543 | struct perf_event *event = vma->vm_file->private_data; |
| 2544 | |
| 2545 | atomic_inc(&event->mmap_count); |
| 2546 | } |
| 2547 | |
| 2548 | static void perf_mmap_close(struct vm_area_struct *vma) |
| 2549 | { |
| 2550 | struct perf_event *event = vma->vm_file->private_data; |
| 2551 | |
| 2552 | WARN_ON_ONCE(event->ctx->parent_ctx); |
| 2553 | if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) { |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2554 | unsigned long size = perf_data_size(event->data); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2555 | struct user_struct *user = current_user(); |
| 2556 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2557 | atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2558 | vma->vm_mm->locked_vm -= event->data->nr_locked; |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2559 | perf_mmap_data_release(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2560 | mutex_unlock(&event->mmap_mutex); |
| 2561 | } |
| 2562 | } |
| 2563 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 2564 | static const struct vm_operations_struct perf_mmap_vmops = { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2565 | .open = perf_mmap_open, |
| 2566 | .close = perf_mmap_close, |
| 2567 | .fault = perf_mmap_fault, |
| 2568 | .page_mkwrite = perf_mmap_fault, |
| 2569 | }; |
| 2570 | |
| 2571 | static int perf_mmap(struct file *file, struct vm_area_struct *vma) |
| 2572 | { |
| 2573 | struct perf_event *event = file->private_data; |
| 2574 | unsigned long user_locked, user_lock_limit; |
| 2575 | struct user_struct *user = current_user(); |
| 2576 | unsigned long locked, lock_limit; |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2577 | struct perf_mmap_data *data; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2578 | unsigned long vma_size; |
| 2579 | unsigned long nr_pages; |
| 2580 | long user_extra, extra; |
| 2581 | int ret = 0; |
| 2582 | |
| 2583 | if (!(vma->vm_flags & VM_SHARED)) |
| 2584 | return -EINVAL; |
| 2585 | |
| 2586 | vma_size = vma->vm_end - vma->vm_start; |
| 2587 | nr_pages = (vma_size / PAGE_SIZE) - 1; |
| 2588 | |
| 2589 | /* |
| 2590 | * If we have data pages ensure they're a power-of-two number, so we |
| 2591 | * can do bitmasks instead of modulo. |
| 2592 | */ |
| 2593 | if (nr_pages != 0 && !is_power_of_2(nr_pages)) |
| 2594 | return -EINVAL; |
| 2595 | |
| 2596 | if (vma_size != PAGE_SIZE * (1 + nr_pages)) |
| 2597 | return -EINVAL; |
| 2598 | |
| 2599 | if (vma->vm_pgoff != 0) |
| 2600 | return -EINVAL; |
| 2601 | |
| 2602 | WARN_ON_ONCE(event->ctx->parent_ctx); |
| 2603 | mutex_lock(&event->mmap_mutex); |
| 2604 | if (event->output) { |
| 2605 | ret = -EINVAL; |
| 2606 | goto unlock; |
| 2607 | } |
| 2608 | |
| 2609 | if (atomic_inc_not_zero(&event->mmap_count)) { |
| 2610 | if (nr_pages != event->data->nr_pages) |
| 2611 | ret = -EINVAL; |
| 2612 | goto unlock; |
| 2613 | } |
| 2614 | |
| 2615 | user_extra = nr_pages + 1; |
| 2616 | user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |
| 2617 | |
| 2618 | /* |
| 2619 | * Increase the limit linearly with more CPUs: |
| 2620 | */ |
| 2621 | user_lock_limit *= num_online_cpus(); |
| 2622 | |
| 2623 | user_locked = atomic_long_read(&user->locked_vm) + user_extra; |
| 2624 | |
| 2625 | extra = 0; |
| 2626 | if (user_locked > user_lock_limit) |
| 2627 | extra = user_locked - user_lock_limit; |
| 2628 | |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 2629 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2630 | lock_limit >>= PAGE_SHIFT; |
| 2631 | locked = vma->vm_mm->locked_vm + extra; |
| 2632 | |
| 2633 | if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && |
| 2634 | !capable(CAP_IPC_LOCK)) { |
| 2635 | ret = -EPERM; |
| 2636 | goto unlock; |
| 2637 | } |
| 2638 | |
| 2639 | WARN_ON(event->data); |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2640 | |
| 2641 | data = perf_mmap_data_alloc(event, nr_pages); |
| 2642 | ret = -ENOMEM; |
| 2643 | if (!data) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2644 | goto unlock; |
| 2645 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2646 | ret = 0; |
| 2647 | perf_mmap_data_init(event, data); |
| 2648 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2649 | atomic_set(&event->mmap_count, 1); |
| 2650 | atomic_long_add(user_extra, &user->locked_vm); |
| 2651 | vma->vm_mm->locked_vm += extra; |
| 2652 | event->data->nr_locked = extra; |
| 2653 | if (vma->vm_flags & VM_WRITE) |
| 2654 | event->data->writable = 1; |
| 2655 | |
| 2656 | unlock: |
| 2657 | mutex_unlock(&event->mmap_mutex); |
| 2658 | |
| 2659 | vma->vm_flags |= VM_RESERVED; |
| 2660 | vma->vm_ops = &perf_mmap_vmops; |
| 2661 | |
| 2662 | return ret; |
| 2663 | } |
| 2664 | |
| 2665 | static int perf_fasync(int fd, struct file *filp, int on) |
| 2666 | { |
| 2667 | struct inode *inode = filp->f_path.dentry->d_inode; |
| 2668 | struct perf_event *event = filp->private_data; |
| 2669 | int retval; |
| 2670 | |
| 2671 | mutex_lock(&inode->i_mutex); |
| 2672 | retval = fasync_helper(fd, filp, on, &event->fasync); |
| 2673 | mutex_unlock(&inode->i_mutex); |
| 2674 | |
| 2675 | if (retval < 0) |
| 2676 | return retval; |
| 2677 | |
| 2678 | return 0; |
| 2679 | } |
| 2680 | |
| 2681 | static const struct file_operations perf_fops = { |
Arnd Bergmann | 3326c1c | 2010-03-23 19:09:33 +0100 | [diff] [blame] | 2682 | .llseek = no_llseek, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2683 | .release = perf_release, |
| 2684 | .read = perf_read, |
| 2685 | .poll = perf_poll, |
| 2686 | .unlocked_ioctl = perf_ioctl, |
| 2687 | .compat_ioctl = perf_ioctl, |
| 2688 | .mmap = perf_mmap, |
| 2689 | .fasync = perf_fasync, |
| 2690 | }; |
| 2691 | |
| 2692 | /* |
| 2693 | * Perf event wakeup |
| 2694 | * |
| 2695 | * If there's data, ensure we set the poll() state and publish everything |
| 2696 | * to user-space before waking everybody up. |
| 2697 | */ |
| 2698 | |
| 2699 | void perf_event_wakeup(struct perf_event *event) |
| 2700 | { |
| 2701 | wake_up_all(&event->waitq); |
| 2702 | |
| 2703 | if (event->pending_kill) { |
| 2704 | kill_fasync(&event->fasync, SIGIO, event->pending_kill); |
| 2705 | event->pending_kill = 0; |
| 2706 | } |
| 2707 | } |
| 2708 | |
| 2709 | /* |
| 2710 | * Pending wakeups |
| 2711 | * |
| 2712 | * Handle the case where we need to wakeup up from NMI (or rq->lock) context. |
| 2713 | * |
| 2714 | * The NMI bit means we cannot possibly take locks. Therefore, maintain a |
| 2715 | * single linked list and use cmpxchg() to add entries lockless. |
| 2716 | */ |
| 2717 | |
| 2718 | static void perf_pending_event(struct perf_pending_entry *entry) |
| 2719 | { |
| 2720 | struct perf_event *event = container_of(entry, |
| 2721 | struct perf_event, pending); |
| 2722 | |
| 2723 | if (event->pending_disable) { |
| 2724 | event->pending_disable = 0; |
| 2725 | __perf_event_disable(event); |
| 2726 | } |
| 2727 | |
| 2728 | if (event->pending_wakeup) { |
| 2729 | event->pending_wakeup = 0; |
| 2730 | perf_event_wakeup(event); |
| 2731 | } |
| 2732 | } |
| 2733 | |
| 2734 | #define PENDING_TAIL ((struct perf_pending_entry *)-1UL) |
| 2735 | |
| 2736 | static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = { |
| 2737 | PENDING_TAIL, |
| 2738 | }; |
| 2739 | |
| 2740 | static void perf_pending_queue(struct perf_pending_entry *entry, |
| 2741 | void (*func)(struct perf_pending_entry *)) |
| 2742 | { |
| 2743 | struct perf_pending_entry **head; |
| 2744 | |
| 2745 | if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL) |
| 2746 | return; |
| 2747 | |
| 2748 | entry->func = func; |
| 2749 | |
| 2750 | head = &get_cpu_var(perf_pending_head); |
| 2751 | |
| 2752 | do { |
| 2753 | entry->next = *head; |
| 2754 | } while (cmpxchg(head, entry->next, entry) != entry->next); |
| 2755 | |
| 2756 | set_perf_event_pending(); |
| 2757 | |
| 2758 | put_cpu_var(perf_pending_head); |
| 2759 | } |
| 2760 | |
| 2761 | static int __perf_pending_run(void) |
| 2762 | { |
| 2763 | struct perf_pending_entry *list; |
| 2764 | int nr = 0; |
| 2765 | |
| 2766 | list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL); |
| 2767 | while (list != PENDING_TAIL) { |
| 2768 | void (*func)(struct perf_pending_entry *); |
| 2769 | struct perf_pending_entry *entry = list; |
| 2770 | |
| 2771 | list = list->next; |
| 2772 | |
| 2773 | func = entry->func; |
| 2774 | entry->next = NULL; |
| 2775 | /* |
| 2776 | * Ensure we observe the unqueue before we issue the wakeup, |
| 2777 | * so that we won't be waiting forever. |
| 2778 | * -- see perf_not_pending(). |
| 2779 | */ |
| 2780 | smp_wmb(); |
| 2781 | |
| 2782 | func(entry); |
| 2783 | nr++; |
| 2784 | } |
| 2785 | |
| 2786 | return nr; |
| 2787 | } |
| 2788 | |
| 2789 | static inline int perf_not_pending(struct perf_event *event) |
| 2790 | { |
| 2791 | /* |
| 2792 | * If we flush on whatever cpu we run, there is a chance we don't |
| 2793 | * need to wait. |
| 2794 | */ |
| 2795 | get_cpu(); |
| 2796 | __perf_pending_run(); |
| 2797 | put_cpu(); |
| 2798 | |
| 2799 | /* |
| 2800 | * Ensure we see the proper queue state before going to sleep |
| 2801 | * so that we do not miss the wakeup. -- see perf_pending_handle() |
| 2802 | */ |
| 2803 | smp_rmb(); |
| 2804 | return event->pending.next == NULL; |
| 2805 | } |
| 2806 | |
| 2807 | static void perf_pending_sync(struct perf_event *event) |
| 2808 | { |
| 2809 | wait_event(event->waitq, perf_not_pending(event)); |
| 2810 | } |
| 2811 | |
| 2812 | void perf_event_do_pending(void) |
| 2813 | { |
| 2814 | __perf_pending_run(); |
| 2815 | } |
| 2816 | |
| 2817 | /* |
| 2818 | * Callchain support -- arch specific |
| 2819 | */ |
| 2820 | |
| 2821 | __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) |
| 2822 | { |
| 2823 | return NULL; |
| 2824 | } |
| 2825 | |
Frederic Weisbecker | 5331d7b | 2010-03-04 21:15:56 +0100 | [diff] [blame] | 2826 | __weak |
| 2827 | void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip) |
| 2828 | { |
| 2829 | } |
Frederic Weisbecker | 26d80aa | 2010-04-03 12:22:05 +0200 | [diff] [blame] | 2830 | |
Frederic Weisbecker | 5331d7b | 2010-03-04 21:15:56 +0100 | [diff] [blame] | 2831 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2832 | /* |
Zhang, Yanmin | 39447b3 | 2010-04-19 13:32:41 +0800 | [diff] [blame] | 2833 | * We assume there is only KVM supporting the callbacks. |
| 2834 | * Later on, we might change it to a list if there is |
| 2835 | * another virtualization implementation supporting the callbacks. |
| 2836 | */ |
| 2837 | struct perf_guest_info_callbacks *perf_guest_cbs; |
| 2838 | |
| 2839 | int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) |
| 2840 | { |
| 2841 | perf_guest_cbs = cbs; |
| 2842 | return 0; |
| 2843 | } |
| 2844 | EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); |
| 2845 | |
| 2846 | int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) |
| 2847 | { |
| 2848 | perf_guest_cbs = NULL; |
| 2849 | return 0; |
| 2850 | } |
| 2851 | EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); |
| 2852 | |
| 2853 | /* |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2854 | * Output |
| 2855 | */ |
| 2856 | static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, |
| 2857 | unsigned long offset, unsigned long head) |
| 2858 | { |
| 2859 | unsigned long mask; |
| 2860 | |
| 2861 | if (!data->writable) |
| 2862 | return true; |
| 2863 | |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2864 | mask = perf_data_size(data) - 1; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2865 | |
| 2866 | offset = (offset - tail) & mask; |
| 2867 | head = (head - tail) & mask; |
| 2868 | |
| 2869 | if ((int)(head - offset) < 0) |
| 2870 | return false; |
| 2871 | |
| 2872 | return true; |
| 2873 | } |
| 2874 | |
| 2875 | static void perf_output_wakeup(struct perf_output_handle *handle) |
| 2876 | { |
| 2877 | atomic_set(&handle->data->poll, POLL_IN); |
| 2878 | |
| 2879 | if (handle->nmi) { |
| 2880 | handle->event->pending_wakeup = 1; |
| 2881 | perf_pending_queue(&handle->event->pending, |
| 2882 | perf_pending_event); |
| 2883 | } else |
| 2884 | perf_event_wakeup(handle->event); |
| 2885 | } |
| 2886 | |
| 2887 | /* |
| 2888 | * Curious locking construct. |
| 2889 | * |
| 2890 | * We need to ensure a later event_id doesn't publish a head when a former |
| 2891 | * event_id isn't done writing. However since we need to deal with NMIs we |
| 2892 | * cannot fully serialize things. |
| 2893 | * |
| 2894 | * What we do is serialize between CPUs so we only have to deal with NMI |
| 2895 | * nesting on a single CPU. |
| 2896 | * |
| 2897 | * We only publish the head (and generate a wakeup) when the outer-most |
| 2898 | * event_id completes. |
| 2899 | */ |
| 2900 | static void perf_output_lock(struct perf_output_handle *handle) |
| 2901 | { |
| 2902 | struct perf_mmap_data *data = handle->data; |
Peter Zijlstra | 559fdc3 | 2009-11-16 12:45:14 +0100 | [diff] [blame] | 2903 | int cur, cpu = get_cpu(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2904 | |
| 2905 | handle->locked = 0; |
| 2906 | |
Peter Zijlstra | 559fdc3 | 2009-11-16 12:45:14 +0100 | [diff] [blame] | 2907 | for (;;) { |
| 2908 | cur = atomic_cmpxchg(&data->lock, -1, cpu); |
| 2909 | if (cur == -1) { |
| 2910 | handle->locked = 1; |
| 2911 | break; |
| 2912 | } |
| 2913 | if (cur == cpu) |
| 2914 | break; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2915 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2916 | cpu_relax(); |
Peter Zijlstra | 559fdc3 | 2009-11-16 12:45:14 +0100 | [diff] [blame] | 2917 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2918 | } |
| 2919 | |
| 2920 | static void perf_output_unlock(struct perf_output_handle *handle) |
| 2921 | { |
| 2922 | struct perf_mmap_data *data = handle->data; |
| 2923 | unsigned long head; |
| 2924 | int cpu; |
| 2925 | |
| 2926 | data->done_head = data->head; |
| 2927 | |
| 2928 | if (!handle->locked) |
| 2929 | goto out; |
| 2930 | |
| 2931 | again: |
| 2932 | /* |
| 2933 | * The xchg implies a full barrier that ensures all writes are done |
| 2934 | * before we publish the new head, matched by a rmb() in userspace when |
| 2935 | * reading this position. |
| 2936 | */ |
| 2937 | while ((head = atomic_long_xchg(&data->done_head, 0))) |
| 2938 | data->user_page->data_head = head; |
| 2939 | |
| 2940 | /* |
| 2941 | * NMI can happen here, which means we can miss a done_head update. |
| 2942 | */ |
| 2943 | |
| 2944 | cpu = atomic_xchg(&data->lock, -1); |
| 2945 | WARN_ON_ONCE(cpu != smp_processor_id()); |
| 2946 | |
| 2947 | /* |
| 2948 | * Therefore we have to validate we did not indeed do so. |
| 2949 | */ |
| 2950 | if (unlikely(atomic_long_read(&data->done_head))) { |
| 2951 | /* |
| 2952 | * Since we had it locked, we can lock it again. |
| 2953 | */ |
| 2954 | while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) |
| 2955 | cpu_relax(); |
| 2956 | |
| 2957 | goto again; |
| 2958 | } |
| 2959 | |
| 2960 | if (atomic_xchg(&data->wakeup, 0)) |
| 2961 | perf_output_wakeup(handle); |
| 2962 | out: |
Peter Zijlstra | 559fdc3 | 2009-11-16 12:45:14 +0100 | [diff] [blame] | 2963 | put_cpu(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2964 | } |
| 2965 | |
| 2966 | void perf_output_copy(struct perf_output_handle *handle, |
| 2967 | const void *buf, unsigned int len) |
| 2968 | { |
| 2969 | unsigned int pages_mask; |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2970 | unsigned long offset; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2971 | unsigned int size; |
| 2972 | void **pages; |
| 2973 | |
| 2974 | offset = handle->offset; |
| 2975 | pages_mask = handle->data->nr_pages - 1; |
| 2976 | pages = handle->data->data_pages; |
| 2977 | |
| 2978 | do { |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2979 | unsigned long page_offset; |
| 2980 | unsigned long page_size; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2981 | int nr; |
| 2982 | |
| 2983 | nr = (offset >> PAGE_SHIFT) & pages_mask; |
Peter Zijlstra | 906010b | 2009-09-21 16:08:49 +0200 | [diff] [blame] | 2984 | page_size = 1UL << (handle->data->data_order + PAGE_SHIFT); |
| 2985 | page_offset = offset & (page_size - 1); |
| 2986 | size = min_t(unsigned int, page_size - page_offset, len); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 2987 | |
| 2988 | memcpy(pages[nr] + page_offset, buf, size); |
| 2989 | |
| 2990 | len -= size; |
| 2991 | buf += size; |
| 2992 | offset += size; |
| 2993 | } while (len); |
| 2994 | |
| 2995 | handle->offset = offset; |
| 2996 | |
| 2997 | /* |
| 2998 | * Check we didn't copy past our reservation window, taking the |
| 2999 | * possible unsigned int wrap into account. |
| 3000 | */ |
| 3001 | WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); |
| 3002 | } |
| 3003 | |
| 3004 | int perf_output_begin(struct perf_output_handle *handle, |
| 3005 | struct perf_event *event, unsigned int size, |
| 3006 | int nmi, int sample) |
| 3007 | { |
| 3008 | struct perf_event *output_event; |
| 3009 | struct perf_mmap_data *data; |
| 3010 | unsigned long tail, offset, head; |
| 3011 | int have_lost; |
| 3012 | struct { |
| 3013 | struct perf_event_header header; |
| 3014 | u64 id; |
| 3015 | u64 lost; |
| 3016 | } lost_event; |
| 3017 | |
| 3018 | rcu_read_lock(); |
| 3019 | /* |
| 3020 | * For inherited events we send all the output towards the parent. |
| 3021 | */ |
| 3022 | if (event->parent) |
| 3023 | event = event->parent; |
| 3024 | |
| 3025 | output_event = rcu_dereference(event->output); |
| 3026 | if (output_event) |
| 3027 | event = output_event; |
| 3028 | |
| 3029 | data = rcu_dereference(event->data); |
| 3030 | if (!data) |
| 3031 | goto out; |
| 3032 | |
| 3033 | handle->data = data; |
| 3034 | handle->event = event; |
| 3035 | handle->nmi = nmi; |
| 3036 | handle->sample = sample; |
| 3037 | |
| 3038 | if (!data->nr_pages) |
| 3039 | goto fail; |
| 3040 | |
| 3041 | have_lost = atomic_read(&data->lost); |
| 3042 | if (have_lost) |
| 3043 | size += sizeof(lost_event); |
| 3044 | |
| 3045 | perf_output_lock(handle); |
| 3046 | |
| 3047 | do { |
| 3048 | /* |
| 3049 | * Userspace could choose to issue a mb() before updating the |
| 3050 | * tail pointer. So that all reads will be completed before the |
| 3051 | * write is issued. |
| 3052 | */ |
| 3053 | tail = ACCESS_ONCE(data->user_page->data_tail); |
| 3054 | smp_rmb(); |
| 3055 | offset = head = atomic_long_read(&data->head); |
| 3056 | head += size; |
| 3057 | if (unlikely(!perf_output_space(data, tail, offset, head))) |
| 3058 | goto fail; |
| 3059 | } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); |
| 3060 | |
| 3061 | handle->offset = offset; |
| 3062 | handle->head = head; |
| 3063 | |
| 3064 | if (head - tail > data->watermark) |
| 3065 | atomic_set(&data->wakeup, 1); |
| 3066 | |
| 3067 | if (have_lost) { |
| 3068 | lost_event.header.type = PERF_RECORD_LOST; |
| 3069 | lost_event.header.misc = 0; |
| 3070 | lost_event.header.size = sizeof(lost_event); |
| 3071 | lost_event.id = event->id; |
| 3072 | lost_event.lost = atomic_xchg(&data->lost, 0); |
| 3073 | |
| 3074 | perf_output_put(handle, lost_event); |
| 3075 | } |
| 3076 | |
| 3077 | return 0; |
| 3078 | |
| 3079 | fail: |
| 3080 | atomic_inc(&data->lost); |
| 3081 | perf_output_unlock(handle); |
| 3082 | out: |
| 3083 | rcu_read_unlock(); |
| 3084 | |
| 3085 | return -ENOSPC; |
| 3086 | } |
| 3087 | |
| 3088 | void perf_output_end(struct perf_output_handle *handle) |
| 3089 | { |
| 3090 | struct perf_event *event = handle->event; |
| 3091 | struct perf_mmap_data *data = handle->data; |
| 3092 | |
| 3093 | int wakeup_events = event->attr.wakeup_events; |
| 3094 | |
| 3095 | if (handle->sample && wakeup_events) { |
| 3096 | int events = atomic_inc_return(&data->events); |
| 3097 | if (events >= wakeup_events) { |
| 3098 | atomic_sub(wakeup_events, &data->events); |
| 3099 | atomic_set(&data->wakeup, 1); |
| 3100 | } |
| 3101 | } |
| 3102 | |
| 3103 | perf_output_unlock(handle); |
| 3104 | rcu_read_unlock(); |
| 3105 | } |
| 3106 | |
| 3107 | static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) |
| 3108 | { |
| 3109 | /* |
| 3110 | * only top level events have the pid namespace they were created in |
| 3111 | */ |
| 3112 | if (event->parent) |
| 3113 | event = event->parent; |
| 3114 | |
| 3115 | return task_tgid_nr_ns(p, event->ns); |
| 3116 | } |
| 3117 | |
| 3118 | static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) |
| 3119 | { |
| 3120 | /* |
| 3121 | * only top level events have the pid namespace they were created in |
| 3122 | */ |
| 3123 | if (event->parent) |
| 3124 | event = event->parent; |
| 3125 | |
| 3126 | return task_pid_nr_ns(p, event->ns); |
| 3127 | } |
| 3128 | |
| 3129 | static void perf_output_read_one(struct perf_output_handle *handle, |
| 3130 | struct perf_event *event) |
| 3131 | { |
| 3132 | u64 read_format = event->attr.read_format; |
| 3133 | u64 values[4]; |
| 3134 | int n = 0; |
| 3135 | |
| 3136 | values[n++] = atomic64_read(&event->count); |
| 3137 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { |
| 3138 | values[n++] = event->total_time_enabled + |
| 3139 | atomic64_read(&event->child_total_time_enabled); |
| 3140 | } |
| 3141 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { |
| 3142 | values[n++] = event->total_time_running + |
| 3143 | atomic64_read(&event->child_total_time_running); |
| 3144 | } |
| 3145 | if (read_format & PERF_FORMAT_ID) |
| 3146 | values[n++] = primary_event_id(event); |
| 3147 | |
| 3148 | perf_output_copy(handle, values, n * sizeof(u64)); |
| 3149 | } |
| 3150 | |
| 3151 | /* |
| 3152 | * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. |
| 3153 | */ |
| 3154 | static void perf_output_read_group(struct perf_output_handle *handle, |
| 3155 | struct perf_event *event) |
| 3156 | { |
| 3157 | struct perf_event *leader = event->group_leader, *sub; |
| 3158 | u64 read_format = event->attr.read_format; |
| 3159 | u64 values[5]; |
| 3160 | int n = 0; |
| 3161 | |
| 3162 | values[n++] = 1 + leader->nr_siblings; |
| 3163 | |
| 3164 | if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) |
| 3165 | values[n++] = leader->total_time_enabled; |
| 3166 | |
| 3167 | if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) |
| 3168 | values[n++] = leader->total_time_running; |
| 3169 | |
| 3170 | if (leader != event) |
| 3171 | leader->pmu->read(leader); |
| 3172 | |
| 3173 | values[n++] = atomic64_read(&leader->count); |
| 3174 | if (read_format & PERF_FORMAT_ID) |
| 3175 | values[n++] = primary_event_id(leader); |
| 3176 | |
| 3177 | perf_output_copy(handle, values, n * sizeof(u64)); |
| 3178 | |
| 3179 | list_for_each_entry(sub, &leader->sibling_list, group_entry) { |
| 3180 | n = 0; |
| 3181 | |
| 3182 | if (sub != event) |
| 3183 | sub->pmu->read(sub); |
| 3184 | |
| 3185 | values[n++] = atomic64_read(&sub->count); |
| 3186 | if (read_format & PERF_FORMAT_ID) |
| 3187 | values[n++] = primary_event_id(sub); |
| 3188 | |
| 3189 | perf_output_copy(handle, values, n * sizeof(u64)); |
| 3190 | } |
| 3191 | } |
| 3192 | |
| 3193 | static void perf_output_read(struct perf_output_handle *handle, |
| 3194 | struct perf_event *event) |
| 3195 | { |
| 3196 | if (event->attr.read_format & PERF_FORMAT_GROUP) |
| 3197 | perf_output_read_group(handle, event); |
| 3198 | else |
| 3199 | perf_output_read_one(handle, event); |
| 3200 | } |
| 3201 | |
| 3202 | void perf_output_sample(struct perf_output_handle *handle, |
| 3203 | struct perf_event_header *header, |
| 3204 | struct perf_sample_data *data, |
| 3205 | struct perf_event *event) |
| 3206 | { |
| 3207 | u64 sample_type = data->type; |
| 3208 | |
| 3209 | perf_output_put(handle, *header); |
| 3210 | |
| 3211 | if (sample_type & PERF_SAMPLE_IP) |
| 3212 | perf_output_put(handle, data->ip); |
| 3213 | |
| 3214 | if (sample_type & PERF_SAMPLE_TID) |
| 3215 | perf_output_put(handle, data->tid_entry); |
| 3216 | |
| 3217 | if (sample_type & PERF_SAMPLE_TIME) |
| 3218 | perf_output_put(handle, data->time); |
| 3219 | |
| 3220 | if (sample_type & PERF_SAMPLE_ADDR) |
| 3221 | perf_output_put(handle, data->addr); |
| 3222 | |
| 3223 | if (sample_type & PERF_SAMPLE_ID) |
| 3224 | perf_output_put(handle, data->id); |
| 3225 | |
| 3226 | if (sample_type & PERF_SAMPLE_STREAM_ID) |
| 3227 | perf_output_put(handle, data->stream_id); |
| 3228 | |
| 3229 | if (sample_type & PERF_SAMPLE_CPU) |
| 3230 | perf_output_put(handle, data->cpu_entry); |
| 3231 | |
| 3232 | if (sample_type & PERF_SAMPLE_PERIOD) |
| 3233 | perf_output_put(handle, data->period); |
| 3234 | |
| 3235 | if (sample_type & PERF_SAMPLE_READ) |
| 3236 | perf_output_read(handle, event); |
| 3237 | |
| 3238 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
| 3239 | if (data->callchain) { |
| 3240 | int size = 1; |
| 3241 | |
| 3242 | if (data->callchain) |
| 3243 | size += data->callchain->nr; |
| 3244 | |
| 3245 | size *= sizeof(u64); |
| 3246 | |
| 3247 | perf_output_copy(handle, data->callchain, size); |
| 3248 | } else { |
| 3249 | u64 nr = 0; |
| 3250 | perf_output_put(handle, nr); |
| 3251 | } |
| 3252 | } |
| 3253 | |
| 3254 | if (sample_type & PERF_SAMPLE_RAW) { |
| 3255 | if (data->raw) { |
| 3256 | perf_output_put(handle, data->raw->size); |
| 3257 | perf_output_copy(handle, data->raw->data, |
| 3258 | data->raw->size); |
| 3259 | } else { |
| 3260 | struct { |
| 3261 | u32 size; |
| 3262 | u32 data; |
| 3263 | } raw = { |
| 3264 | .size = sizeof(u32), |
| 3265 | .data = 0, |
| 3266 | }; |
| 3267 | perf_output_put(handle, raw); |
| 3268 | } |
| 3269 | } |
| 3270 | } |
| 3271 | |
| 3272 | void perf_prepare_sample(struct perf_event_header *header, |
| 3273 | struct perf_sample_data *data, |
| 3274 | struct perf_event *event, |
| 3275 | struct pt_regs *regs) |
| 3276 | { |
| 3277 | u64 sample_type = event->attr.sample_type; |
| 3278 | |
| 3279 | data->type = sample_type; |
| 3280 | |
| 3281 | header->type = PERF_RECORD_SAMPLE; |
| 3282 | header->size = sizeof(*header); |
| 3283 | |
| 3284 | header->misc = 0; |
| 3285 | header->misc |= perf_misc_flags(regs); |
| 3286 | |
| 3287 | if (sample_type & PERF_SAMPLE_IP) { |
| 3288 | data->ip = perf_instruction_pointer(regs); |
| 3289 | |
| 3290 | header->size += sizeof(data->ip); |
| 3291 | } |
| 3292 | |
| 3293 | if (sample_type & PERF_SAMPLE_TID) { |
| 3294 | /* namespace issues */ |
| 3295 | data->tid_entry.pid = perf_event_pid(event, current); |
| 3296 | data->tid_entry.tid = perf_event_tid(event, current); |
| 3297 | |
| 3298 | header->size += sizeof(data->tid_entry); |
| 3299 | } |
| 3300 | |
| 3301 | if (sample_type & PERF_SAMPLE_TIME) { |
| 3302 | data->time = perf_clock(); |
| 3303 | |
| 3304 | header->size += sizeof(data->time); |
| 3305 | } |
| 3306 | |
| 3307 | if (sample_type & PERF_SAMPLE_ADDR) |
| 3308 | header->size += sizeof(data->addr); |
| 3309 | |
| 3310 | if (sample_type & PERF_SAMPLE_ID) { |
| 3311 | data->id = primary_event_id(event); |
| 3312 | |
| 3313 | header->size += sizeof(data->id); |
| 3314 | } |
| 3315 | |
| 3316 | if (sample_type & PERF_SAMPLE_STREAM_ID) { |
| 3317 | data->stream_id = event->id; |
| 3318 | |
| 3319 | header->size += sizeof(data->stream_id); |
| 3320 | } |
| 3321 | |
| 3322 | if (sample_type & PERF_SAMPLE_CPU) { |
| 3323 | data->cpu_entry.cpu = raw_smp_processor_id(); |
| 3324 | data->cpu_entry.reserved = 0; |
| 3325 | |
| 3326 | header->size += sizeof(data->cpu_entry); |
| 3327 | } |
| 3328 | |
| 3329 | if (sample_type & PERF_SAMPLE_PERIOD) |
| 3330 | header->size += sizeof(data->period); |
| 3331 | |
| 3332 | if (sample_type & PERF_SAMPLE_READ) |
| 3333 | header->size += perf_event_read_size(event); |
| 3334 | |
| 3335 | if (sample_type & PERF_SAMPLE_CALLCHAIN) { |
| 3336 | int size = 1; |
| 3337 | |
| 3338 | data->callchain = perf_callchain(regs); |
| 3339 | |
| 3340 | if (data->callchain) |
| 3341 | size += data->callchain->nr; |
| 3342 | |
| 3343 | header->size += size * sizeof(u64); |
| 3344 | } |
| 3345 | |
| 3346 | if (sample_type & PERF_SAMPLE_RAW) { |
| 3347 | int size = sizeof(u32); |
| 3348 | |
| 3349 | if (data->raw) |
| 3350 | size += data->raw->size; |
| 3351 | else |
| 3352 | size += sizeof(u32); |
| 3353 | |
| 3354 | WARN_ON_ONCE(size & (sizeof(u64)-1)); |
| 3355 | header->size += size; |
| 3356 | } |
| 3357 | } |
| 3358 | |
| 3359 | static void perf_event_output(struct perf_event *event, int nmi, |
| 3360 | struct perf_sample_data *data, |
| 3361 | struct pt_regs *regs) |
| 3362 | { |
| 3363 | struct perf_output_handle handle; |
| 3364 | struct perf_event_header header; |
| 3365 | |
| 3366 | perf_prepare_sample(&header, data, event, regs); |
| 3367 | |
| 3368 | if (perf_output_begin(&handle, event, header.size, nmi, 1)) |
| 3369 | return; |
| 3370 | |
| 3371 | perf_output_sample(&handle, &header, data, event); |
| 3372 | |
| 3373 | perf_output_end(&handle); |
| 3374 | } |
| 3375 | |
| 3376 | /* |
| 3377 | * read event_id |
| 3378 | */ |
| 3379 | |
| 3380 | struct perf_read_event { |
| 3381 | struct perf_event_header header; |
| 3382 | |
| 3383 | u32 pid; |
| 3384 | u32 tid; |
| 3385 | }; |
| 3386 | |
| 3387 | static void |
| 3388 | perf_event_read_event(struct perf_event *event, |
| 3389 | struct task_struct *task) |
| 3390 | { |
| 3391 | struct perf_output_handle handle; |
| 3392 | struct perf_read_event read_event = { |
| 3393 | .header = { |
| 3394 | .type = PERF_RECORD_READ, |
| 3395 | .misc = 0, |
| 3396 | .size = sizeof(read_event) + perf_event_read_size(event), |
| 3397 | }, |
| 3398 | .pid = perf_event_pid(event, task), |
| 3399 | .tid = perf_event_tid(event, task), |
| 3400 | }; |
| 3401 | int ret; |
| 3402 | |
| 3403 | ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0); |
| 3404 | if (ret) |
| 3405 | return; |
| 3406 | |
| 3407 | perf_output_put(&handle, read_event); |
| 3408 | perf_output_read(&handle, event); |
| 3409 | |
| 3410 | perf_output_end(&handle); |
| 3411 | } |
| 3412 | |
| 3413 | /* |
| 3414 | * task tracking -- fork/exit |
| 3415 | * |
| 3416 | * enabled by: attr.comm | attr.mmap | attr.task |
| 3417 | */ |
| 3418 | |
| 3419 | struct perf_task_event { |
| 3420 | struct task_struct *task; |
| 3421 | struct perf_event_context *task_ctx; |
| 3422 | |
| 3423 | struct { |
| 3424 | struct perf_event_header header; |
| 3425 | |
| 3426 | u32 pid; |
| 3427 | u32 ppid; |
| 3428 | u32 tid; |
| 3429 | u32 ptid; |
| 3430 | u64 time; |
| 3431 | } event_id; |
| 3432 | }; |
| 3433 | |
| 3434 | static void perf_event_task_output(struct perf_event *event, |
| 3435 | struct perf_task_event *task_event) |
| 3436 | { |
| 3437 | struct perf_output_handle handle; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3438 | struct task_struct *task = task_event->task; |
Mike Galbraith | 8bb39f9 | 2010-03-26 11:11:33 +0100 | [diff] [blame] | 3439 | unsigned long flags; |
| 3440 | int size, ret; |
| 3441 | |
| 3442 | /* |
| 3443 | * If this CPU attempts to acquire an rq lock held by a CPU spinning |
| 3444 | * in perf_output_lock() from interrupt context, it's game over. |
| 3445 | */ |
| 3446 | local_irq_save(flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3447 | |
| 3448 | size = task_event->event_id.header.size; |
| 3449 | ret = perf_output_begin(&handle, event, size, 0, 0); |
| 3450 | |
Mike Galbraith | 8bb39f9 | 2010-03-26 11:11:33 +0100 | [diff] [blame] | 3451 | if (ret) { |
| 3452 | local_irq_restore(flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3453 | return; |
Mike Galbraith | 8bb39f9 | 2010-03-26 11:11:33 +0100 | [diff] [blame] | 3454 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3455 | |
| 3456 | task_event->event_id.pid = perf_event_pid(event, task); |
| 3457 | task_event->event_id.ppid = perf_event_pid(event, current); |
| 3458 | |
| 3459 | task_event->event_id.tid = perf_event_tid(event, task); |
| 3460 | task_event->event_id.ptid = perf_event_tid(event, current); |
| 3461 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3462 | perf_output_put(&handle, task_event->event_id); |
| 3463 | |
| 3464 | perf_output_end(&handle); |
Mike Galbraith | 8bb39f9 | 2010-03-26 11:11:33 +0100 | [diff] [blame] | 3465 | local_irq_restore(flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3466 | } |
| 3467 | |
| 3468 | static int perf_event_task_match(struct perf_event *event) |
| 3469 | { |
Peter Zijlstra | 6f93d0a | 2010-02-14 11:12:04 +0100 | [diff] [blame] | 3470 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
Peter Zijlstra | 22e1908 | 2010-01-18 09:12:32 +0100 | [diff] [blame] | 3471 | return 0; |
| 3472 | |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3473 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 3474 | return 0; |
| 3475 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3476 | if (event->attr.comm || event->attr.mmap || event->attr.task) |
| 3477 | return 1; |
| 3478 | |
| 3479 | return 0; |
| 3480 | } |
| 3481 | |
| 3482 | static void perf_event_task_ctx(struct perf_event_context *ctx, |
| 3483 | struct perf_task_event *task_event) |
| 3484 | { |
| 3485 | struct perf_event *event; |
| 3486 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3487 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
| 3488 | if (perf_event_task_match(event)) |
| 3489 | perf_event_task_output(event, task_event); |
| 3490 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3491 | } |
| 3492 | |
| 3493 | static void perf_event_task_event(struct perf_task_event *task_event) |
| 3494 | { |
| 3495 | struct perf_cpu_context *cpuctx; |
| 3496 | struct perf_event_context *ctx = task_event->task_ctx; |
| 3497 | |
Peter Zijlstra | d6ff86c | 2009-11-20 22:19:46 +0100 | [diff] [blame] | 3498 | rcu_read_lock(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3499 | cpuctx = &get_cpu_var(perf_cpu_context); |
| 3500 | perf_event_task_ctx(&cpuctx->ctx, task_event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3501 | if (!ctx) |
Peter Zijlstra | 6f93d0a | 2010-02-14 11:12:04 +0100 | [diff] [blame] | 3502 | ctx = rcu_dereference(current->perf_event_ctxp); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3503 | if (ctx) |
| 3504 | perf_event_task_ctx(ctx, task_event); |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3505 | put_cpu_var(perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3506 | rcu_read_unlock(); |
| 3507 | } |
| 3508 | |
| 3509 | static void perf_event_task(struct task_struct *task, |
| 3510 | struct perf_event_context *task_ctx, |
| 3511 | int new) |
| 3512 | { |
| 3513 | struct perf_task_event task_event; |
| 3514 | |
| 3515 | if (!atomic_read(&nr_comm_events) && |
| 3516 | !atomic_read(&nr_mmap_events) && |
| 3517 | !atomic_read(&nr_task_events)) |
| 3518 | return; |
| 3519 | |
| 3520 | task_event = (struct perf_task_event){ |
| 3521 | .task = task, |
| 3522 | .task_ctx = task_ctx, |
| 3523 | .event_id = { |
| 3524 | .header = { |
| 3525 | .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, |
| 3526 | .misc = 0, |
| 3527 | .size = sizeof(task_event.event_id), |
| 3528 | }, |
| 3529 | /* .pid */ |
| 3530 | /* .ppid */ |
| 3531 | /* .tid */ |
| 3532 | /* .ptid */ |
Peter Zijlstra | 6f93d0a | 2010-02-14 11:12:04 +0100 | [diff] [blame] | 3533 | .time = perf_clock(), |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3534 | }, |
| 3535 | }; |
| 3536 | |
| 3537 | perf_event_task_event(&task_event); |
| 3538 | } |
| 3539 | |
| 3540 | void perf_event_fork(struct task_struct *task) |
| 3541 | { |
| 3542 | perf_event_task(task, NULL, 1); |
| 3543 | } |
| 3544 | |
| 3545 | /* |
| 3546 | * comm tracking |
| 3547 | */ |
| 3548 | |
| 3549 | struct perf_comm_event { |
| 3550 | struct task_struct *task; |
| 3551 | char *comm; |
| 3552 | int comm_size; |
| 3553 | |
| 3554 | struct { |
| 3555 | struct perf_event_header header; |
| 3556 | |
| 3557 | u32 pid; |
| 3558 | u32 tid; |
| 3559 | } event_id; |
| 3560 | }; |
| 3561 | |
| 3562 | static void perf_event_comm_output(struct perf_event *event, |
| 3563 | struct perf_comm_event *comm_event) |
| 3564 | { |
| 3565 | struct perf_output_handle handle; |
| 3566 | int size = comm_event->event_id.header.size; |
| 3567 | int ret = perf_output_begin(&handle, event, size, 0, 0); |
| 3568 | |
| 3569 | if (ret) |
| 3570 | return; |
| 3571 | |
| 3572 | comm_event->event_id.pid = perf_event_pid(event, comm_event->task); |
| 3573 | comm_event->event_id.tid = perf_event_tid(event, comm_event->task); |
| 3574 | |
| 3575 | perf_output_put(&handle, comm_event->event_id); |
| 3576 | perf_output_copy(&handle, comm_event->comm, |
| 3577 | comm_event->comm_size); |
| 3578 | perf_output_end(&handle); |
| 3579 | } |
| 3580 | |
| 3581 | static int perf_event_comm_match(struct perf_event *event) |
| 3582 | { |
Peter Zijlstra | 6f93d0a | 2010-02-14 11:12:04 +0100 | [diff] [blame] | 3583 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
Peter Zijlstra | 22e1908 | 2010-01-18 09:12:32 +0100 | [diff] [blame] | 3584 | return 0; |
| 3585 | |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3586 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 3587 | return 0; |
| 3588 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3589 | if (event->attr.comm) |
| 3590 | return 1; |
| 3591 | |
| 3592 | return 0; |
| 3593 | } |
| 3594 | |
| 3595 | static void perf_event_comm_ctx(struct perf_event_context *ctx, |
| 3596 | struct perf_comm_event *comm_event) |
| 3597 | { |
| 3598 | struct perf_event *event; |
| 3599 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3600 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
| 3601 | if (perf_event_comm_match(event)) |
| 3602 | perf_event_comm_output(event, comm_event); |
| 3603 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3604 | } |
| 3605 | |
| 3606 | static void perf_event_comm_event(struct perf_comm_event *comm_event) |
| 3607 | { |
| 3608 | struct perf_cpu_context *cpuctx; |
| 3609 | struct perf_event_context *ctx; |
| 3610 | unsigned int size; |
| 3611 | char comm[TASK_COMM_LEN]; |
| 3612 | |
| 3613 | memset(comm, 0, sizeof(comm)); |
Márton Németh | 96b02d7 | 2009-11-21 23:10:15 +0100 | [diff] [blame] | 3614 | strlcpy(comm, comm_event->task->comm, sizeof(comm)); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3615 | size = ALIGN(strlen(comm)+1, sizeof(u64)); |
| 3616 | |
| 3617 | comm_event->comm = comm; |
| 3618 | comm_event->comm_size = size; |
| 3619 | |
| 3620 | comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; |
| 3621 | |
Peter Zijlstra | f6595f3 | 2009-11-20 22:19:47 +0100 | [diff] [blame] | 3622 | rcu_read_lock(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3623 | cpuctx = &get_cpu_var(perf_cpu_context); |
| 3624 | perf_event_comm_ctx(&cpuctx->ctx, comm_event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3625 | ctx = rcu_dereference(current->perf_event_ctxp); |
| 3626 | if (ctx) |
| 3627 | perf_event_comm_ctx(ctx, comm_event); |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3628 | put_cpu_var(perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3629 | rcu_read_unlock(); |
| 3630 | } |
| 3631 | |
| 3632 | void perf_event_comm(struct task_struct *task) |
| 3633 | { |
| 3634 | struct perf_comm_event comm_event; |
| 3635 | |
| 3636 | if (task->perf_event_ctxp) |
| 3637 | perf_event_enable_on_exec(task); |
| 3638 | |
| 3639 | if (!atomic_read(&nr_comm_events)) |
| 3640 | return; |
| 3641 | |
| 3642 | comm_event = (struct perf_comm_event){ |
| 3643 | .task = task, |
| 3644 | /* .comm */ |
| 3645 | /* .comm_size */ |
| 3646 | .event_id = { |
| 3647 | .header = { |
| 3648 | .type = PERF_RECORD_COMM, |
| 3649 | .misc = 0, |
| 3650 | /* .size */ |
| 3651 | }, |
| 3652 | /* .pid */ |
| 3653 | /* .tid */ |
| 3654 | }, |
| 3655 | }; |
| 3656 | |
| 3657 | perf_event_comm_event(&comm_event); |
| 3658 | } |
| 3659 | |
| 3660 | /* |
| 3661 | * mmap tracking |
| 3662 | */ |
| 3663 | |
| 3664 | struct perf_mmap_event { |
| 3665 | struct vm_area_struct *vma; |
| 3666 | |
| 3667 | const char *file_name; |
| 3668 | int file_size; |
| 3669 | |
| 3670 | struct { |
| 3671 | struct perf_event_header header; |
| 3672 | |
| 3673 | u32 pid; |
| 3674 | u32 tid; |
| 3675 | u64 start; |
| 3676 | u64 len; |
| 3677 | u64 pgoff; |
| 3678 | } event_id; |
| 3679 | }; |
| 3680 | |
| 3681 | static void perf_event_mmap_output(struct perf_event *event, |
| 3682 | struct perf_mmap_event *mmap_event) |
| 3683 | { |
| 3684 | struct perf_output_handle handle; |
| 3685 | int size = mmap_event->event_id.header.size; |
| 3686 | int ret = perf_output_begin(&handle, event, size, 0, 0); |
| 3687 | |
| 3688 | if (ret) |
| 3689 | return; |
| 3690 | |
| 3691 | mmap_event->event_id.pid = perf_event_pid(event, current); |
| 3692 | mmap_event->event_id.tid = perf_event_tid(event, current); |
| 3693 | |
| 3694 | perf_output_put(&handle, mmap_event->event_id); |
| 3695 | perf_output_copy(&handle, mmap_event->file_name, |
| 3696 | mmap_event->file_size); |
| 3697 | perf_output_end(&handle); |
| 3698 | } |
| 3699 | |
| 3700 | static int perf_event_mmap_match(struct perf_event *event, |
| 3701 | struct perf_mmap_event *mmap_event) |
| 3702 | { |
Peter Zijlstra | 6f93d0a | 2010-02-14 11:12:04 +0100 | [diff] [blame] | 3703 | if (event->state < PERF_EVENT_STATE_INACTIVE) |
Peter Zijlstra | 22e1908 | 2010-01-18 09:12:32 +0100 | [diff] [blame] | 3704 | return 0; |
| 3705 | |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3706 | if (event->cpu != -1 && event->cpu != smp_processor_id()) |
| 3707 | return 0; |
| 3708 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3709 | if (event->attr.mmap) |
| 3710 | return 1; |
| 3711 | |
| 3712 | return 0; |
| 3713 | } |
| 3714 | |
| 3715 | static void perf_event_mmap_ctx(struct perf_event_context *ctx, |
| 3716 | struct perf_mmap_event *mmap_event) |
| 3717 | { |
| 3718 | struct perf_event *event; |
| 3719 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3720 | list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { |
| 3721 | if (perf_event_mmap_match(event, mmap_event)) |
| 3722 | perf_event_mmap_output(event, mmap_event); |
| 3723 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3724 | } |
| 3725 | |
| 3726 | static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) |
| 3727 | { |
| 3728 | struct perf_cpu_context *cpuctx; |
| 3729 | struct perf_event_context *ctx; |
| 3730 | struct vm_area_struct *vma = mmap_event->vma; |
| 3731 | struct file *file = vma->vm_file; |
| 3732 | unsigned int size; |
| 3733 | char tmp[16]; |
| 3734 | char *buf = NULL; |
| 3735 | const char *name; |
| 3736 | |
| 3737 | memset(tmp, 0, sizeof(tmp)); |
| 3738 | |
| 3739 | if (file) { |
| 3740 | /* |
| 3741 | * d_path works from the end of the buffer backwards, so we |
| 3742 | * need to add enough zero bytes after the string to handle |
| 3743 | * the 64bit alignment we do later. |
| 3744 | */ |
| 3745 | buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL); |
| 3746 | if (!buf) { |
| 3747 | name = strncpy(tmp, "//enomem", sizeof(tmp)); |
| 3748 | goto got_name; |
| 3749 | } |
| 3750 | name = d_path(&file->f_path, buf, PATH_MAX); |
| 3751 | if (IS_ERR(name)) { |
| 3752 | name = strncpy(tmp, "//toolong", sizeof(tmp)); |
| 3753 | goto got_name; |
| 3754 | } |
| 3755 | } else { |
| 3756 | if (arch_vma_name(mmap_event->vma)) { |
| 3757 | name = strncpy(tmp, arch_vma_name(mmap_event->vma), |
| 3758 | sizeof(tmp)); |
| 3759 | goto got_name; |
| 3760 | } |
| 3761 | |
| 3762 | if (!vma->vm_mm) { |
| 3763 | name = strncpy(tmp, "[vdso]", sizeof(tmp)); |
| 3764 | goto got_name; |
| 3765 | } |
| 3766 | |
| 3767 | name = strncpy(tmp, "//anon", sizeof(tmp)); |
| 3768 | goto got_name; |
| 3769 | } |
| 3770 | |
| 3771 | got_name: |
| 3772 | size = ALIGN(strlen(name)+1, sizeof(u64)); |
| 3773 | |
| 3774 | mmap_event->file_name = name; |
| 3775 | mmap_event->file_size = size; |
| 3776 | |
| 3777 | mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; |
| 3778 | |
Peter Zijlstra | f6d9dd2 | 2009-11-20 22:19:48 +0100 | [diff] [blame] | 3779 | rcu_read_lock(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3780 | cpuctx = &get_cpu_var(perf_cpu_context); |
| 3781 | perf_event_mmap_ctx(&cpuctx->ctx, mmap_event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3782 | ctx = rcu_dereference(current->perf_event_ctxp); |
| 3783 | if (ctx) |
| 3784 | perf_event_mmap_ctx(ctx, mmap_event); |
Peter Zijlstra | 5d27c23 | 2009-12-17 13:16:32 +0100 | [diff] [blame] | 3785 | put_cpu_var(perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3786 | rcu_read_unlock(); |
| 3787 | |
| 3788 | kfree(buf); |
| 3789 | } |
| 3790 | |
| 3791 | void __perf_event_mmap(struct vm_area_struct *vma) |
| 3792 | { |
| 3793 | struct perf_mmap_event mmap_event; |
| 3794 | |
| 3795 | if (!atomic_read(&nr_mmap_events)) |
| 3796 | return; |
| 3797 | |
| 3798 | mmap_event = (struct perf_mmap_event){ |
| 3799 | .vma = vma, |
| 3800 | /* .file_name */ |
| 3801 | /* .file_size */ |
| 3802 | .event_id = { |
| 3803 | .header = { |
| 3804 | .type = PERF_RECORD_MMAP, |
Zhang, Yanmin | 39447b3 | 2010-04-19 13:32:41 +0800 | [diff] [blame] | 3805 | .misc = PERF_RECORD_MISC_USER, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3806 | /* .size */ |
| 3807 | }, |
| 3808 | /* .pid */ |
| 3809 | /* .tid */ |
| 3810 | .start = vma->vm_start, |
| 3811 | .len = vma->vm_end - vma->vm_start, |
Peter Zijlstra | 3a0304e | 2010-02-26 10:33:41 +0100 | [diff] [blame] | 3812 | .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3813 | }, |
| 3814 | }; |
| 3815 | |
| 3816 | perf_event_mmap_event(&mmap_event); |
| 3817 | } |
| 3818 | |
| 3819 | /* |
| 3820 | * IRQ throttle logging |
| 3821 | */ |
| 3822 | |
| 3823 | static void perf_log_throttle(struct perf_event *event, int enable) |
| 3824 | { |
| 3825 | struct perf_output_handle handle; |
| 3826 | int ret; |
| 3827 | |
| 3828 | struct { |
| 3829 | struct perf_event_header header; |
| 3830 | u64 time; |
| 3831 | u64 id; |
| 3832 | u64 stream_id; |
| 3833 | } throttle_event = { |
| 3834 | .header = { |
| 3835 | .type = PERF_RECORD_THROTTLE, |
| 3836 | .misc = 0, |
| 3837 | .size = sizeof(throttle_event), |
| 3838 | }, |
| 3839 | .time = perf_clock(), |
| 3840 | .id = primary_event_id(event), |
| 3841 | .stream_id = event->id, |
| 3842 | }; |
| 3843 | |
| 3844 | if (enable) |
| 3845 | throttle_event.header.type = PERF_RECORD_UNTHROTTLE; |
| 3846 | |
| 3847 | ret = perf_output_begin(&handle, event, sizeof(throttle_event), 1, 0); |
| 3848 | if (ret) |
| 3849 | return; |
| 3850 | |
| 3851 | perf_output_put(&handle, throttle_event); |
| 3852 | perf_output_end(&handle); |
| 3853 | } |
| 3854 | |
| 3855 | /* |
| 3856 | * Generic event overflow handling, sampling. |
| 3857 | */ |
| 3858 | |
| 3859 | static int __perf_event_overflow(struct perf_event *event, int nmi, |
| 3860 | int throttle, struct perf_sample_data *data, |
| 3861 | struct pt_regs *regs) |
| 3862 | { |
| 3863 | int events = atomic_read(&event->event_limit); |
| 3864 | struct hw_perf_event *hwc = &event->hw; |
| 3865 | int ret = 0; |
| 3866 | |
| 3867 | throttle = (throttle && event->pmu->unthrottle != NULL); |
| 3868 | |
| 3869 | if (!throttle) { |
| 3870 | hwc->interrupts++; |
| 3871 | } else { |
| 3872 | if (hwc->interrupts != MAX_INTERRUPTS) { |
| 3873 | hwc->interrupts++; |
| 3874 | if (HZ * hwc->interrupts > |
| 3875 | (u64)sysctl_perf_event_sample_rate) { |
| 3876 | hwc->interrupts = MAX_INTERRUPTS; |
| 3877 | perf_log_throttle(event, 0); |
| 3878 | ret = 1; |
| 3879 | } |
| 3880 | } else { |
| 3881 | /* |
| 3882 | * Keep re-disabling events even though on the previous |
| 3883 | * pass we disabled it - just in case we raced with a |
| 3884 | * sched-in and the event got enabled again: |
| 3885 | */ |
| 3886 | ret = 1; |
| 3887 | } |
| 3888 | } |
| 3889 | |
| 3890 | if (event->attr.freq) { |
| 3891 | u64 now = perf_clock(); |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 3892 | s64 delta = now - hwc->freq_time_stamp; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3893 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 3894 | hwc->freq_time_stamp = now; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3895 | |
Peter Zijlstra | abd5071 | 2010-01-26 18:50:16 +0100 | [diff] [blame] | 3896 | if (delta > 0 && delta < 2*TICK_NSEC) |
| 3897 | perf_adjust_period(event, delta, hwc->last_period); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3898 | } |
| 3899 | |
| 3900 | /* |
| 3901 | * XXX event_limit might not quite work as expected on inherited |
| 3902 | * events |
| 3903 | */ |
| 3904 | |
| 3905 | event->pending_kill = POLL_IN; |
| 3906 | if (events && atomic_dec_and_test(&event->event_limit)) { |
| 3907 | ret = 1; |
| 3908 | event->pending_kill = POLL_HUP; |
| 3909 | if (nmi) { |
| 3910 | event->pending_disable = 1; |
| 3911 | perf_pending_queue(&event->pending, |
| 3912 | perf_pending_event); |
| 3913 | } else |
| 3914 | perf_event_disable(event); |
| 3915 | } |
| 3916 | |
Peter Zijlstra | 453f19e | 2009-11-20 22:19:43 +0100 | [diff] [blame] | 3917 | if (event->overflow_handler) |
| 3918 | event->overflow_handler(event, nmi, data, regs); |
| 3919 | else |
| 3920 | perf_event_output(event, nmi, data, regs); |
| 3921 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3922 | return ret; |
| 3923 | } |
| 3924 | |
| 3925 | int perf_event_overflow(struct perf_event *event, int nmi, |
| 3926 | struct perf_sample_data *data, |
| 3927 | struct pt_regs *regs) |
| 3928 | { |
| 3929 | return __perf_event_overflow(event, nmi, 1, data, regs); |
| 3930 | } |
| 3931 | |
| 3932 | /* |
| 3933 | * Generic software event infrastructure |
| 3934 | */ |
| 3935 | |
| 3936 | /* |
| 3937 | * We directly increment event->count and keep a second value in |
| 3938 | * event->hw.period_left to count intervals. This period event |
| 3939 | * is kept in the range [-sample_period, 0] so that we can use the |
| 3940 | * sign as trigger. |
| 3941 | */ |
| 3942 | |
| 3943 | static u64 perf_swevent_set_period(struct perf_event *event) |
| 3944 | { |
| 3945 | struct hw_perf_event *hwc = &event->hw; |
| 3946 | u64 period = hwc->last_period; |
| 3947 | u64 nr, offset; |
| 3948 | s64 old, val; |
| 3949 | |
| 3950 | hwc->last_period = hwc->sample_period; |
| 3951 | |
| 3952 | again: |
| 3953 | old = val = atomic64_read(&hwc->period_left); |
| 3954 | if (val < 0) |
| 3955 | return 0; |
| 3956 | |
| 3957 | nr = div64_u64(period + val, period); |
| 3958 | offset = nr * period; |
| 3959 | val -= offset; |
| 3960 | if (atomic64_cmpxchg(&hwc->period_left, old, val) != old) |
| 3961 | goto again; |
| 3962 | |
| 3963 | return nr; |
| 3964 | } |
| 3965 | |
Peter Zijlstra | 0cff784 | 2009-11-20 22:19:44 +0100 | [diff] [blame] | 3966 | static void perf_swevent_overflow(struct perf_event *event, u64 overflow, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3967 | int nmi, struct perf_sample_data *data, |
| 3968 | struct pt_regs *regs) |
| 3969 | { |
| 3970 | struct hw_perf_event *hwc = &event->hw; |
| 3971 | int throttle = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3972 | |
| 3973 | data->period = event->hw.last_period; |
Peter Zijlstra | 0cff784 | 2009-11-20 22:19:44 +0100 | [diff] [blame] | 3974 | if (!overflow) |
| 3975 | overflow = perf_swevent_set_period(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 3976 | |
| 3977 | if (hwc->interrupts == MAX_INTERRUPTS) |
| 3978 | return; |
| 3979 | |
| 3980 | for (; overflow; overflow--) { |
| 3981 | if (__perf_event_overflow(event, nmi, throttle, |
| 3982 | data, regs)) { |
| 3983 | /* |
| 3984 | * We inhibit the overflow from happening when |
| 3985 | * hwc->interrupts == MAX_INTERRUPTS. |
| 3986 | */ |
| 3987 | break; |
| 3988 | } |
| 3989 | throttle = 1; |
| 3990 | } |
| 3991 | } |
| 3992 | |
| 3993 | static void perf_swevent_unthrottle(struct perf_event *event) |
| 3994 | { |
| 3995 | /* |
| 3996 | * Nothing to do, we already reset hwc->interrupts. |
| 3997 | */ |
| 3998 | } |
| 3999 | |
| 4000 | static void perf_swevent_add(struct perf_event *event, u64 nr, |
| 4001 | int nmi, struct perf_sample_data *data, |
| 4002 | struct pt_regs *regs) |
| 4003 | { |
| 4004 | struct hw_perf_event *hwc = &event->hw; |
| 4005 | |
| 4006 | atomic64_add(nr, &event->count); |
| 4007 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4008 | if (!regs) |
| 4009 | return; |
| 4010 | |
Peter Zijlstra | 0cff784 | 2009-11-20 22:19:44 +0100 | [diff] [blame] | 4011 | if (!hwc->sample_period) |
| 4012 | return; |
| 4013 | |
| 4014 | if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) |
| 4015 | return perf_swevent_overflow(event, 1, nmi, data, regs); |
| 4016 | |
| 4017 | if (atomic64_add_negative(nr, &hwc->period_left)) |
| 4018 | return; |
| 4019 | |
| 4020 | perf_swevent_overflow(event, 0, nmi, data, regs); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4021 | } |
| 4022 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4023 | static int perf_tp_event_match(struct perf_event *event, |
| 4024 | struct perf_sample_data *data); |
| 4025 | |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4026 | static int perf_exclude_event(struct perf_event *event, |
| 4027 | struct pt_regs *regs) |
| 4028 | { |
| 4029 | if (regs) { |
| 4030 | if (event->attr.exclude_user && user_mode(regs)) |
| 4031 | return 1; |
| 4032 | |
| 4033 | if (event->attr.exclude_kernel && !user_mode(regs)) |
| 4034 | return 1; |
| 4035 | } |
| 4036 | |
| 4037 | return 0; |
| 4038 | } |
| 4039 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4040 | static int perf_swevent_match(struct perf_event *event, |
| 4041 | enum perf_type_id type, |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4042 | u32 event_id, |
| 4043 | struct perf_sample_data *data, |
| 4044 | struct pt_regs *regs) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4045 | { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4046 | if (event->attr.type != type) |
| 4047 | return 0; |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4048 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4049 | if (event->attr.config != event_id) |
| 4050 | return 0; |
| 4051 | |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4052 | if (perf_exclude_event(event, regs)) |
| 4053 | return 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4054 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4055 | if (event->attr.type == PERF_TYPE_TRACEPOINT && |
| 4056 | !perf_tp_event_match(event, data)) |
| 4057 | return 0; |
| 4058 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4059 | return 1; |
| 4060 | } |
| 4061 | |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4062 | static inline u64 swevent_hash(u64 type, u32 event_id) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4063 | { |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4064 | u64 val = event_id | (type << 32); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4065 | |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4066 | return hash_64(val, SWEVENT_HLIST_BITS); |
| 4067 | } |
| 4068 | |
| 4069 | static struct hlist_head * |
| 4070 | find_swevent_head(struct perf_cpu_context *ctx, u64 type, u32 event_id) |
| 4071 | { |
| 4072 | u64 hash; |
| 4073 | struct swevent_hlist *hlist; |
| 4074 | |
| 4075 | hash = swevent_hash(type, event_id); |
| 4076 | |
| 4077 | hlist = rcu_dereference(ctx->swevent_hlist); |
| 4078 | if (!hlist) |
| 4079 | return NULL; |
| 4080 | |
| 4081 | return &hlist->heads[hash]; |
| 4082 | } |
| 4083 | |
| 4084 | static void do_perf_sw_event(enum perf_type_id type, u32 event_id, |
| 4085 | u64 nr, int nmi, |
| 4086 | struct perf_sample_data *data, |
| 4087 | struct pt_regs *regs) |
| 4088 | { |
| 4089 | struct perf_cpu_context *cpuctx; |
| 4090 | struct perf_event *event; |
| 4091 | struct hlist_node *node; |
| 4092 | struct hlist_head *head; |
| 4093 | |
| 4094 | cpuctx = &__get_cpu_var(perf_cpu_context); |
| 4095 | |
| 4096 | rcu_read_lock(); |
| 4097 | |
| 4098 | head = find_swevent_head(cpuctx, type, event_id); |
| 4099 | |
| 4100 | if (!head) |
| 4101 | goto end; |
| 4102 | |
| 4103 | hlist_for_each_entry_rcu(event, node, head, hlist_entry) { |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4104 | if (perf_swevent_match(event, type, event_id, data, regs)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4105 | perf_swevent_add(event, nr, nmi, data, regs); |
| 4106 | } |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4107 | end: |
| 4108 | rcu_read_unlock(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4109 | } |
| 4110 | |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4111 | int perf_swevent_get_recursion_context(void) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4112 | { |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4113 | struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); |
| 4114 | int rctx; |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4115 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4116 | if (in_nmi()) |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4117 | rctx = 3; |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4118 | else if (in_irq()) |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4119 | rctx = 2; |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4120 | else if (in_softirq()) |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4121 | rctx = 1; |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4122 | else |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4123 | rctx = 0; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4124 | |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4125 | if (cpuctx->recursion[rctx]) { |
| 4126 | put_cpu_var(perf_cpu_context); |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4127 | return -1; |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4128 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4129 | |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4130 | cpuctx->recursion[rctx]++; |
| 4131 | barrier(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4132 | |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4133 | return rctx; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4134 | } |
Ingo Molnar | 645e8cc | 2009-11-22 12:20:19 +0100 | [diff] [blame] | 4135 | EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4136 | |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4137 | void perf_swevent_put_recursion_context(int rctx) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4138 | { |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4139 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 4140 | barrier(); |
Frederic Weisbecker | fe61267 | 2009-11-24 20:38:22 +0100 | [diff] [blame] | 4141 | cpuctx->recursion[rctx]--; |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4142 | put_cpu_var(perf_cpu_context); |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4143 | } |
Ingo Molnar | 645e8cc | 2009-11-22 12:20:19 +0100 | [diff] [blame] | 4144 | EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context); |
Frederic Weisbecker | ce71b9d | 2009-11-22 05:26:55 +0100 | [diff] [blame] | 4145 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4146 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4147 | void __perf_sw_event(u32 event_id, u64 nr, int nmi, |
| 4148 | struct pt_regs *regs, u64 addr) |
| 4149 | { |
Ingo Molnar | a4234bf | 2009-11-23 10:57:59 +0100 | [diff] [blame] | 4150 | struct perf_sample_data data; |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4151 | int rctx; |
| 4152 | |
| 4153 | rctx = perf_swevent_get_recursion_context(); |
| 4154 | if (rctx < 0) |
| 4155 | return; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4156 | |
Peter Zijlstra | dc1d628 | 2010-03-03 15:55:04 +0100 | [diff] [blame] | 4157 | perf_sample_data_init(&data, addr); |
Ingo Molnar | a4234bf | 2009-11-23 10:57:59 +0100 | [diff] [blame] | 4158 | |
| 4159 | do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs); |
Peter Zijlstra | 4ed7c92 | 2009-11-23 11:37:29 +0100 | [diff] [blame] | 4160 | |
| 4161 | perf_swevent_put_recursion_context(rctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4162 | } |
| 4163 | |
| 4164 | static void perf_swevent_read(struct perf_event *event) |
| 4165 | { |
| 4166 | } |
| 4167 | |
| 4168 | static int perf_swevent_enable(struct perf_event *event) |
| 4169 | { |
| 4170 | struct hw_perf_event *hwc = &event->hw; |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4171 | struct perf_cpu_context *cpuctx; |
| 4172 | struct hlist_head *head; |
| 4173 | |
| 4174 | cpuctx = &__get_cpu_var(perf_cpu_context); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4175 | |
| 4176 | if (hwc->sample_period) { |
| 4177 | hwc->last_period = hwc->sample_period; |
| 4178 | perf_swevent_set_period(event); |
| 4179 | } |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4180 | |
| 4181 | head = find_swevent_head(cpuctx, event->attr.type, event->attr.config); |
| 4182 | if (WARN_ON_ONCE(!head)) |
| 4183 | return -EINVAL; |
| 4184 | |
| 4185 | hlist_add_head_rcu(&event->hlist_entry, head); |
| 4186 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4187 | return 0; |
| 4188 | } |
| 4189 | |
| 4190 | static void perf_swevent_disable(struct perf_event *event) |
| 4191 | { |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4192 | hlist_del_rcu(&event->hlist_entry); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4193 | } |
| 4194 | |
| 4195 | static const struct pmu perf_ops_generic = { |
| 4196 | .enable = perf_swevent_enable, |
| 4197 | .disable = perf_swevent_disable, |
| 4198 | .read = perf_swevent_read, |
| 4199 | .unthrottle = perf_swevent_unthrottle, |
| 4200 | }; |
| 4201 | |
| 4202 | /* |
| 4203 | * hrtimer based swevent callback |
| 4204 | */ |
| 4205 | |
| 4206 | static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) |
| 4207 | { |
| 4208 | enum hrtimer_restart ret = HRTIMER_RESTART; |
| 4209 | struct perf_sample_data data; |
| 4210 | struct pt_regs *regs; |
| 4211 | struct perf_event *event; |
| 4212 | u64 period; |
| 4213 | |
Peter Zijlstra | dc1d628 | 2010-03-03 15:55:04 +0100 | [diff] [blame] | 4214 | event = container_of(hrtimer, struct perf_event, hw.hrtimer); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4215 | event->pmu->read(event); |
| 4216 | |
Peter Zijlstra | dc1d628 | 2010-03-03 15:55:04 +0100 | [diff] [blame] | 4217 | perf_sample_data_init(&data, 0); |
Xiao Guangrong | 59d069e | 2009-12-01 17:30:08 +0800 | [diff] [blame] | 4218 | data.period = event->hw.last_period; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4219 | regs = get_irq_regs(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4220 | |
Frederic Weisbecker | df8290b | 2010-04-09 00:28:14 +0200 | [diff] [blame] | 4221 | if (regs && !perf_exclude_event(event, regs)) { |
Soeren Sandmann | 54f4407 | 2009-10-22 18:34:08 +0200 | [diff] [blame] | 4222 | if (!(event->attr.exclude_idle && current->pid == 0)) |
| 4223 | if (perf_event_overflow(event, 0, &data, regs)) |
| 4224 | ret = HRTIMER_NORESTART; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4225 | } |
| 4226 | |
| 4227 | period = max_t(u64, 10000, event->hw.sample_period); |
| 4228 | hrtimer_forward_now(hrtimer, ns_to_ktime(period)); |
| 4229 | |
| 4230 | return ret; |
| 4231 | } |
| 4232 | |
Soeren Sandmann | 721a669 | 2009-09-15 14:33:08 +0200 | [diff] [blame] | 4233 | static void perf_swevent_start_hrtimer(struct perf_event *event) |
| 4234 | { |
| 4235 | struct hw_perf_event *hwc = &event->hw; |
| 4236 | |
| 4237 | hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| 4238 | hwc->hrtimer.function = perf_swevent_hrtimer; |
| 4239 | if (hwc->sample_period) { |
| 4240 | u64 period; |
| 4241 | |
| 4242 | if (hwc->remaining) { |
| 4243 | if (hwc->remaining < 0) |
| 4244 | period = 10000; |
| 4245 | else |
| 4246 | period = hwc->remaining; |
| 4247 | hwc->remaining = 0; |
| 4248 | } else { |
| 4249 | period = max_t(u64, 10000, hwc->sample_period); |
| 4250 | } |
| 4251 | __hrtimer_start_range_ns(&hwc->hrtimer, |
| 4252 | ns_to_ktime(period), 0, |
| 4253 | HRTIMER_MODE_REL, 0); |
| 4254 | } |
| 4255 | } |
| 4256 | |
| 4257 | static void perf_swevent_cancel_hrtimer(struct perf_event *event) |
| 4258 | { |
| 4259 | struct hw_perf_event *hwc = &event->hw; |
| 4260 | |
| 4261 | if (hwc->sample_period) { |
| 4262 | ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); |
| 4263 | hwc->remaining = ktime_to_ns(remaining); |
| 4264 | |
| 4265 | hrtimer_cancel(&hwc->hrtimer); |
| 4266 | } |
| 4267 | } |
| 4268 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4269 | /* |
| 4270 | * Software event: cpu wall time clock |
| 4271 | */ |
| 4272 | |
| 4273 | static void cpu_clock_perf_event_update(struct perf_event *event) |
| 4274 | { |
| 4275 | int cpu = raw_smp_processor_id(); |
| 4276 | s64 prev; |
| 4277 | u64 now; |
| 4278 | |
| 4279 | now = cpu_clock(cpu); |
Xiao Guangrong | ec89a06f | 2009-12-09 11:30:36 +0800 | [diff] [blame] | 4280 | prev = atomic64_xchg(&event->hw.prev_count, now); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4281 | atomic64_add(now - prev, &event->count); |
| 4282 | } |
| 4283 | |
| 4284 | static int cpu_clock_perf_event_enable(struct perf_event *event) |
| 4285 | { |
| 4286 | struct hw_perf_event *hwc = &event->hw; |
| 4287 | int cpu = raw_smp_processor_id(); |
| 4288 | |
| 4289 | atomic64_set(&hwc->prev_count, cpu_clock(cpu)); |
Soeren Sandmann | 721a669 | 2009-09-15 14:33:08 +0200 | [diff] [blame] | 4290 | perf_swevent_start_hrtimer(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4291 | |
| 4292 | return 0; |
| 4293 | } |
| 4294 | |
| 4295 | static void cpu_clock_perf_event_disable(struct perf_event *event) |
| 4296 | { |
Soeren Sandmann | 721a669 | 2009-09-15 14:33:08 +0200 | [diff] [blame] | 4297 | perf_swevent_cancel_hrtimer(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4298 | cpu_clock_perf_event_update(event); |
| 4299 | } |
| 4300 | |
| 4301 | static void cpu_clock_perf_event_read(struct perf_event *event) |
| 4302 | { |
| 4303 | cpu_clock_perf_event_update(event); |
| 4304 | } |
| 4305 | |
| 4306 | static const struct pmu perf_ops_cpu_clock = { |
| 4307 | .enable = cpu_clock_perf_event_enable, |
| 4308 | .disable = cpu_clock_perf_event_disable, |
| 4309 | .read = cpu_clock_perf_event_read, |
| 4310 | }; |
| 4311 | |
| 4312 | /* |
| 4313 | * Software event: task time clock |
| 4314 | */ |
| 4315 | |
| 4316 | static void task_clock_perf_event_update(struct perf_event *event, u64 now) |
| 4317 | { |
| 4318 | u64 prev; |
| 4319 | s64 delta; |
| 4320 | |
| 4321 | prev = atomic64_xchg(&event->hw.prev_count, now); |
| 4322 | delta = now - prev; |
| 4323 | atomic64_add(delta, &event->count); |
| 4324 | } |
| 4325 | |
| 4326 | static int task_clock_perf_event_enable(struct perf_event *event) |
| 4327 | { |
| 4328 | struct hw_perf_event *hwc = &event->hw; |
| 4329 | u64 now; |
| 4330 | |
| 4331 | now = event->ctx->time; |
| 4332 | |
| 4333 | atomic64_set(&hwc->prev_count, now); |
Soeren Sandmann | 721a669 | 2009-09-15 14:33:08 +0200 | [diff] [blame] | 4334 | |
| 4335 | perf_swevent_start_hrtimer(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4336 | |
| 4337 | return 0; |
| 4338 | } |
| 4339 | |
| 4340 | static void task_clock_perf_event_disable(struct perf_event *event) |
| 4341 | { |
Soeren Sandmann | 721a669 | 2009-09-15 14:33:08 +0200 | [diff] [blame] | 4342 | perf_swevent_cancel_hrtimer(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4343 | task_clock_perf_event_update(event, event->ctx->time); |
| 4344 | |
| 4345 | } |
| 4346 | |
| 4347 | static void task_clock_perf_event_read(struct perf_event *event) |
| 4348 | { |
| 4349 | u64 time; |
| 4350 | |
| 4351 | if (!in_nmi()) { |
| 4352 | update_context_time(event->ctx); |
| 4353 | time = event->ctx->time; |
| 4354 | } else { |
| 4355 | u64 now = perf_clock(); |
| 4356 | u64 delta = now - event->ctx->timestamp; |
| 4357 | time = event->ctx->time + delta; |
| 4358 | } |
| 4359 | |
| 4360 | task_clock_perf_event_update(event, time); |
| 4361 | } |
| 4362 | |
| 4363 | static const struct pmu perf_ops_task_clock = { |
| 4364 | .enable = task_clock_perf_event_enable, |
| 4365 | .disable = task_clock_perf_event_disable, |
| 4366 | .read = task_clock_perf_event_read, |
| 4367 | }; |
| 4368 | |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4369 | static void swevent_hlist_release_rcu(struct rcu_head *rcu_head) |
| 4370 | { |
| 4371 | struct swevent_hlist *hlist; |
| 4372 | |
| 4373 | hlist = container_of(rcu_head, struct swevent_hlist, rcu_head); |
| 4374 | kfree(hlist); |
| 4375 | } |
| 4376 | |
| 4377 | static void swevent_hlist_release(struct perf_cpu_context *cpuctx) |
| 4378 | { |
| 4379 | struct swevent_hlist *hlist; |
| 4380 | |
| 4381 | if (!cpuctx->swevent_hlist) |
| 4382 | return; |
| 4383 | |
| 4384 | hlist = cpuctx->swevent_hlist; |
| 4385 | rcu_assign_pointer(cpuctx->swevent_hlist, NULL); |
| 4386 | call_rcu(&hlist->rcu_head, swevent_hlist_release_rcu); |
| 4387 | } |
| 4388 | |
| 4389 | static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) |
| 4390 | { |
| 4391 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 4392 | |
| 4393 | mutex_lock(&cpuctx->hlist_mutex); |
| 4394 | |
| 4395 | if (!--cpuctx->hlist_refcount) |
| 4396 | swevent_hlist_release(cpuctx); |
| 4397 | |
| 4398 | mutex_unlock(&cpuctx->hlist_mutex); |
| 4399 | } |
| 4400 | |
| 4401 | static void swevent_hlist_put(struct perf_event *event) |
| 4402 | { |
| 4403 | int cpu; |
| 4404 | |
| 4405 | if (event->cpu != -1) { |
| 4406 | swevent_hlist_put_cpu(event, event->cpu); |
| 4407 | return; |
| 4408 | } |
| 4409 | |
| 4410 | for_each_possible_cpu(cpu) |
| 4411 | swevent_hlist_put_cpu(event, cpu); |
| 4412 | } |
| 4413 | |
| 4414 | static int swevent_hlist_get_cpu(struct perf_event *event, int cpu) |
| 4415 | { |
| 4416 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 4417 | int err = 0; |
| 4418 | |
| 4419 | mutex_lock(&cpuctx->hlist_mutex); |
| 4420 | |
| 4421 | if (!cpuctx->swevent_hlist && cpu_online(cpu)) { |
| 4422 | struct swevent_hlist *hlist; |
| 4423 | |
| 4424 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); |
| 4425 | if (!hlist) { |
| 4426 | err = -ENOMEM; |
| 4427 | goto exit; |
| 4428 | } |
| 4429 | rcu_assign_pointer(cpuctx->swevent_hlist, hlist); |
| 4430 | } |
| 4431 | cpuctx->hlist_refcount++; |
| 4432 | exit: |
| 4433 | mutex_unlock(&cpuctx->hlist_mutex); |
| 4434 | |
| 4435 | return err; |
| 4436 | } |
| 4437 | |
| 4438 | static int swevent_hlist_get(struct perf_event *event) |
| 4439 | { |
| 4440 | int err; |
| 4441 | int cpu, failed_cpu; |
| 4442 | |
| 4443 | if (event->cpu != -1) |
| 4444 | return swevent_hlist_get_cpu(event, event->cpu); |
| 4445 | |
| 4446 | get_online_cpus(); |
| 4447 | for_each_possible_cpu(cpu) { |
| 4448 | err = swevent_hlist_get_cpu(event, cpu); |
| 4449 | if (err) { |
| 4450 | failed_cpu = cpu; |
| 4451 | goto fail; |
| 4452 | } |
| 4453 | } |
| 4454 | put_online_cpus(); |
| 4455 | |
| 4456 | return 0; |
| 4457 | fail: |
| 4458 | for_each_possible_cpu(cpu) { |
| 4459 | if (cpu == failed_cpu) |
| 4460 | break; |
| 4461 | swevent_hlist_put_cpu(event, cpu); |
| 4462 | } |
| 4463 | |
| 4464 | put_online_cpus(); |
| 4465 | return err; |
| 4466 | } |
| 4467 | |
Frederic Weisbecker | 95476b6 | 2010-04-14 23:42:18 +0200 | [diff] [blame] | 4468 | #ifdef CONFIG_EVENT_TRACING |
| 4469 | |
| 4470 | void perf_tp_event(int event_id, u64 addr, u64 count, void *record, |
| 4471 | int entry_size, struct pt_regs *regs) |
| 4472 | { |
| 4473 | struct perf_sample_data data; |
| 4474 | struct perf_raw_record raw = { |
| 4475 | .size = entry_size, |
| 4476 | .data = record, |
| 4477 | }; |
| 4478 | |
| 4479 | perf_sample_data_init(&data, addr); |
| 4480 | data.raw = &raw; |
| 4481 | |
| 4482 | /* Trace events already protected against recursion */ |
| 4483 | do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, |
| 4484 | &data, regs); |
| 4485 | } |
| 4486 | EXPORT_SYMBOL_GPL(perf_tp_event); |
| 4487 | |
| 4488 | static int perf_tp_event_match(struct perf_event *event, |
| 4489 | struct perf_sample_data *data) |
| 4490 | { |
| 4491 | void *record = data->raw->data; |
| 4492 | |
| 4493 | if (likely(!event->filter) || filter_match_preds(event->filter, record)) |
| 4494 | return 1; |
| 4495 | return 0; |
| 4496 | } |
| 4497 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4498 | static void tp_perf_event_destroy(struct perf_event *event) |
| 4499 | { |
Frederic Weisbecker | 97d5a22 | 2010-03-05 05:35:37 +0100 | [diff] [blame] | 4500 | perf_trace_disable(event->attr.config); |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4501 | swevent_hlist_put(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4502 | } |
| 4503 | |
| 4504 | static const struct pmu *tp_perf_event_init(struct perf_event *event) |
| 4505 | { |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4506 | int err; |
| 4507 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4508 | /* |
| 4509 | * Raw tracepoint data is a severe data leak, only allow root to |
| 4510 | * have these. |
| 4511 | */ |
| 4512 | if ((event->attr.sample_type & PERF_SAMPLE_RAW) && |
| 4513 | perf_paranoid_tracepoint_raw() && |
| 4514 | !capable(CAP_SYS_ADMIN)) |
| 4515 | return ERR_PTR(-EPERM); |
| 4516 | |
Frederic Weisbecker | 97d5a22 | 2010-03-05 05:35:37 +0100 | [diff] [blame] | 4517 | if (perf_trace_enable(event->attr.config)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4518 | return NULL; |
| 4519 | |
| 4520 | event->destroy = tp_perf_event_destroy; |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4521 | err = swevent_hlist_get(event); |
| 4522 | if (err) { |
| 4523 | perf_trace_disable(event->attr.config); |
| 4524 | return ERR_PTR(err); |
| 4525 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4526 | |
| 4527 | return &perf_ops_generic; |
| 4528 | } |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4529 | |
| 4530 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) |
| 4531 | { |
| 4532 | char *filter_str; |
| 4533 | int ret; |
| 4534 | |
| 4535 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
| 4536 | return -EINVAL; |
| 4537 | |
| 4538 | filter_str = strndup_user(arg, PAGE_SIZE); |
| 4539 | if (IS_ERR(filter_str)) |
| 4540 | return PTR_ERR(filter_str); |
| 4541 | |
| 4542 | ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); |
| 4543 | |
| 4544 | kfree(filter_str); |
| 4545 | return ret; |
| 4546 | } |
| 4547 | |
| 4548 | static void perf_event_free_filter(struct perf_event *event) |
| 4549 | { |
| 4550 | ftrace_profile_free_filter(event); |
| 4551 | } |
| 4552 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4553 | #else |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4554 | |
| 4555 | static int perf_tp_event_match(struct perf_event *event, |
| 4556 | struct perf_sample_data *data) |
| 4557 | { |
| 4558 | return 1; |
| 4559 | } |
| 4560 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4561 | static const struct pmu *tp_perf_event_init(struct perf_event *event) |
| 4562 | { |
| 4563 | return NULL; |
| 4564 | } |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4565 | |
| 4566 | static int perf_event_set_filter(struct perf_event *event, void __user *arg) |
| 4567 | { |
| 4568 | return -ENOENT; |
| 4569 | } |
| 4570 | |
| 4571 | static void perf_event_free_filter(struct perf_event *event) |
| 4572 | { |
| 4573 | } |
| 4574 | |
Li Zefan | 07b139c | 2009-12-21 14:27:35 +0800 | [diff] [blame] | 4575 | #endif /* CONFIG_EVENT_TRACING */ |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4576 | |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4577 | #ifdef CONFIG_HAVE_HW_BREAKPOINT |
| 4578 | static void bp_perf_event_destroy(struct perf_event *event) |
| 4579 | { |
| 4580 | release_bp_slot(event); |
| 4581 | } |
| 4582 | |
| 4583 | static const struct pmu *bp_perf_event_init(struct perf_event *bp) |
| 4584 | { |
| 4585 | int err; |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 4586 | |
| 4587 | err = register_perf_hw_breakpoint(bp); |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4588 | if (err) |
| 4589 | return ERR_PTR(err); |
| 4590 | |
| 4591 | bp->destroy = bp_perf_event_destroy; |
| 4592 | |
| 4593 | return &perf_ops_bp; |
| 4594 | } |
| 4595 | |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4596 | void perf_bp_event(struct perf_event *bp, void *data) |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4597 | { |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4598 | struct perf_sample_data sample; |
| 4599 | struct pt_regs *regs = data; |
| 4600 | |
Peter Zijlstra | dc1d628 | 2010-03-03 15:55:04 +0100 | [diff] [blame] | 4601 | perf_sample_data_init(&sample, bp->attr.bp_addr); |
Frederic Weisbecker | f5ffe02 | 2009-11-23 15:42:34 +0100 | [diff] [blame] | 4602 | |
| 4603 | if (!perf_exclude_event(bp, regs)) |
| 4604 | perf_swevent_add(bp, 1, 1, &sample, regs); |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4605 | } |
| 4606 | #else |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4607 | static const struct pmu *bp_perf_event_init(struct perf_event *bp) |
| 4608 | { |
| 4609 | return NULL; |
| 4610 | } |
| 4611 | |
| 4612 | void perf_bp_event(struct perf_event *bp, void *regs) |
| 4613 | { |
| 4614 | } |
| 4615 | #endif |
| 4616 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4617 | atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; |
| 4618 | |
| 4619 | static void sw_perf_event_destroy(struct perf_event *event) |
| 4620 | { |
| 4621 | u64 event_id = event->attr.config; |
| 4622 | |
| 4623 | WARN_ON(event->parent); |
| 4624 | |
| 4625 | atomic_dec(&perf_swevent_enabled[event_id]); |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4626 | swevent_hlist_put(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4627 | } |
| 4628 | |
| 4629 | static const struct pmu *sw_perf_event_init(struct perf_event *event) |
| 4630 | { |
| 4631 | const struct pmu *pmu = NULL; |
| 4632 | u64 event_id = event->attr.config; |
| 4633 | |
| 4634 | /* |
| 4635 | * Software events (currently) can't in general distinguish |
| 4636 | * between user, kernel and hypervisor events. |
| 4637 | * However, context switches and cpu migrations are considered |
| 4638 | * to be kernel events, and page faults are never hypervisor |
| 4639 | * events. |
| 4640 | */ |
| 4641 | switch (event_id) { |
| 4642 | case PERF_COUNT_SW_CPU_CLOCK: |
| 4643 | pmu = &perf_ops_cpu_clock; |
| 4644 | |
| 4645 | break; |
| 4646 | case PERF_COUNT_SW_TASK_CLOCK: |
| 4647 | /* |
| 4648 | * If the user instantiates this as a per-cpu event, |
| 4649 | * use the cpu_clock event instead. |
| 4650 | */ |
| 4651 | if (event->ctx->task) |
| 4652 | pmu = &perf_ops_task_clock; |
| 4653 | else |
| 4654 | pmu = &perf_ops_cpu_clock; |
| 4655 | |
| 4656 | break; |
| 4657 | case PERF_COUNT_SW_PAGE_FAULTS: |
| 4658 | case PERF_COUNT_SW_PAGE_FAULTS_MIN: |
| 4659 | case PERF_COUNT_SW_PAGE_FAULTS_MAJ: |
| 4660 | case PERF_COUNT_SW_CONTEXT_SWITCHES: |
| 4661 | case PERF_COUNT_SW_CPU_MIGRATIONS: |
Anton Blanchard | f7d7986 | 2009-10-18 01:09:29 +0000 | [diff] [blame] | 4662 | case PERF_COUNT_SW_ALIGNMENT_FAULTS: |
| 4663 | case PERF_COUNT_SW_EMULATION_FAULTS: |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4664 | if (!event->parent) { |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 4665 | int err; |
| 4666 | |
| 4667 | err = swevent_hlist_get(event); |
| 4668 | if (err) |
| 4669 | return ERR_PTR(err); |
| 4670 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4671 | atomic_inc(&perf_swevent_enabled[event_id]); |
| 4672 | event->destroy = sw_perf_event_destroy; |
| 4673 | } |
| 4674 | pmu = &perf_ops_generic; |
| 4675 | break; |
| 4676 | } |
| 4677 | |
| 4678 | return pmu; |
| 4679 | } |
| 4680 | |
| 4681 | /* |
| 4682 | * Allocate and initialize a event structure |
| 4683 | */ |
| 4684 | static struct perf_event * |
| 4685 | perf_event_alloc(struct perf_event_attr *attr, |
| 4686 | int cpu, |
| 4687 | struct perf_event_context *ctx, |
| 4688 | struct perf_event *group_leader, |
| 4689 | struct perf_event *parent_event, |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 4690 | perf_overflow_handler_t overflow_handler, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4691 | gfp_t gfpflags) |
| 4692 | { |
| 4693 | const struct pmu *pmu; |
| 4694 | struct perf_event *event; |
| 4695 | struct hw_perf_event *hwc; |
| 4696 | long err; |
| 4697 | |
| 4698 | event = kzalloc(sizeof(*event), gfpflags); |
| 4699 | if (!event) |
| 4700 | return ERR_PTR(-ENOMEM); |
| 4701 | |
| 4702 | /* |
| 4703 | * Single events are their own group leaders, with an |
| 4704 | * empty sibling list: |
| 4705 | */ |
| 4706 | if (!group_leader) |
| 4707 | group_leader = event; |
| 4708 | |
| 4709 | mutex_init(&event->child_mutex); |
| 4710 | INIT_LIST_HEAD(&event->child_list); |
| 4711 | |
| 4712 | INIT_LIST_HEAD(&event->group_entry); |
| 4713 | INIT_LIST_HEAD(&event->event_entry); |
| 4714 | INIT_LIST_HEAD(&event->sibling_list); |
| 4715 | init_waitqueue_head(&event->waitq); |
| 4716 | |
| 4717 | mutex_init(&event->mmap_mutex); |
| 4718 | |
| 4719 | event->cpu = cpu; |
| 4720 | event->attr = *attr; |
| 4721 | event->group_leader = group_leader; |
| 4722 | event->pmu = NULL; |
| 4723 | event->ctx = ctx; |
| 4724 | event->oncpu = -1; |
| 4725 | |
| 4726 | event->parent = parent_event; |
| 4727 | |
| 4728 | event->ns = get_pid_ns(current->nsproxy->pid_ns); |
| 4729 | event->id = atomic64_inc_return(&perf_event_id); |
| 4730 | |
| 4731 | event->state = PERF_EVENT_STATE_INACTIVE; |
| 4732 | |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 4733 | if (!overflow_handler && parent_event) |
| 4734 | overflow_handler = parent_event->overflow_handler; |
Frederic Weisbecker | 97eaf53 | 2009-10-18 15:33:50 +0200 | [diff] [blame] | 4735 | |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 4736 | event->overflow_handler = overflow_handler; |
Frederic Weisbecker | 97eaf53 | 2009-10-18 15:33:50 +0200 | [diff] [blame] | 4737 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4738 | if (attr->disabled) |
| 4739 | event->state = PERF_EVENT_STATE_OFF; |
| 4740 | |
| 4741 | pmu = NULL; |
| 4742 | |
| 4743 | hwc = &event->hw; |
| 4744 | hwc->sample_period = attr->sample_period; |
| 4745 | if (attr->freq && attr->sample_freq) |
| 4746 | hwc->sample_period = 1; |
| 4747 | hwc->last_period = hwc->sample_period; |
| 4748 | |
| 4749 | atomic64_set(&hwc->period_left, hwc->sample_period); |
| 4750 | |
| 4751 | /* |
| 4752 | * we currently do not support PERF_FORMAT_GROUP on inherited events |
| 4753 | */ |
| 4754 | if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) |
| 4755 | goto done; |
| 4756 | |
| 4757 | switch (attr->type) { |
| 4758 | case PERF_TYPE_RAW: |
| 4759 | case PERF_TYPE_HARDWARE: |
| 4760 | case PERF_TYPE_HW_CACHE: |
| 4761 | pmu = hw_perf_event_init(event); |
| 4762 | break; |
| 4763 | |
| 4764 | case PERF_TYPE_SOFTWARE: |
| 4765 | pmu = sw_perf_event_init(event); |
| 4766 | break; |
| 4767 | |
| 4768 | case PERF_TYPE_TRACEPOINT: |
| 4769 | pmu = tp_perf_event_init(event); |
| 4770 | break; |
| 4771 | |
Frederic Weisbecker | 24f1e32c | 2009-09-09 19:22:48 +0200 | [diff] [blame] | 4772 | case PERF_TYPE_BREAKPOINT: |
| 4773 | pmu = bp_perf_event_init(event); |
| 4774 | break; |
| 4775 | |
| 4776 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4777 | default: |
| 4778 | break; |
| 4779 | } |
| 4780 | done: |
| 4781 | err = 0; |
| 4782 | if (!pmu) |
| 4783 | err = -EINVAL; |
| 4784 | else if (IS_ERR(pmu)) |
| 4785 | err = PTR_ERR(pmu); |
| 4786 | |
| 4787 | if (err) { |
| 4788 | if (event->ns) |
| 4789 | put_pid_ns(event->ns); |
| 4790 | kfree(event); |
| 4791 | return ERR_PTR(err); |
| 4792 | } |
| 4793 | |
| 4794 | event->pmu = pmu; |
| 4795 | |
| 4796 | if (!event->parent) { |
| 4797 | atomic_inc(&nr_events); |
| 4798 | if (event->attr.mmap) |
| 4799 | atomic_inc(&nr_mmap_events); |
| 4800 | if (event->attr.comm) |
| 4801 | atomic_inc(&nr_comm_events); |
| 4802 | if (event->attr.task) |
| 4803 | atomic_inc(&nr_task_events); |
| 4804 | } |
| 4805 | |
| 4806 | return event; |
| 4807 | } |
| 4808 | |
| 4809 | static int perf_copy_attr(struct perf_event_attr __user *uattr, |
| 4810 | struct perf_event_attr *attr) |
| 4811 | { |
| 4812 | u32 size; |
| 4813 | int ret; |
| 4814 | |
| 4815 | if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) |
| 4816 | return -EFAULT; |
| 4817 | |
| 4818 | /* |
| 4819 | * zero the full structure, so that a short copy will be nice. |
| 4820 | */ |
| 4821 | memset(attr, 0, sizeof(*attr)); |
| 4822 | |
| 4823 | ret = get_user(size, &uattr->size); |
| 4824 | if (ret) |
| 4825 | return ret; |
| 4826 | |
| 4827 | if (size > PAGE_SIZE) /* silly large */ |
| 4828 | goto err_size; |
| 4829 | |
| 4830 | if (!size) /* abi compat */ |
| 4831 | size = PERF_ATTR_SIZE_VER0; |
| 4832 | |
| 4833 | if (size < PERF_ATTR_SIZE_VER0) |
| 4834 | goto err_size; |
| 4835 | |
| 4836 | /* |
| 4837 | * If we're handed a bigger struct than we know of, |
| 4838 | * ensure all the unknown bits are 0 - i.e. new |
| 4839 | * user-space does not rely on any kernel feature |
| 4840 | * extensions we dont know about yet. |
| 4841 | */ |
| 4842 | if (size > sizeof(*attr)) { |
| 4843 | unsigned char __user *addr; |
| 4844 | unsigned char __user *end; |
| 4845 | unsigned char val; |
| 4846 | |
| 4847 | addr = (void __user *)uattr + sizeof(*attr); |
| 4848 | end = (void __user *)uattr + size; |
| 4849 | |
| 4850 | for (; addr < end; addr++) { |
| 4851 | ret = get_user(val, addr); |
| 4852 | if (ret) |
| 4853 | return ret; |
| 4854 | if (val) |
| 4855 | goto err_size; |
| 4856 | } |
| 4857 | size = sizeof(*attr); |
| 4858 | } |
| 4859 | |
| 4860 | ret = copy_from_user(attr, uattr, size); |
| 4861 | if (ret) |
| 4862 | return -EFAULT; |
| 4863 | |
| 4864 | /* |
| 4865 | * If the type exists, the corresponding creation will verify |
| 4866 | * the attr->config. |
| 4867 | */ |
| 4868 | if (attr->type >= PERF_TYPE_MAX) |
| 4869 | return -EINVAL; |
| 4870 | |
Mahesh Salgaonkar | cd75764 | 2010-01-30 10:25:18 +0530 | [diff] [blame] | 4871 | if (attr->__reserved_1) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4872 | return -EINVAL; |
| 4873 | |
| 4874 | if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) |
| 4875 | return -EINVAL; |
| 4876 | |
| 4877 | if (attr->read_format & ~(PERF_FORMAT_MAX-1)) |
| 4878 | return -EINVAL; |
| 4879 | |
| 4880 | out: |
| 4881 | return ret; |
| 4882 | |
| 4883 | err_size: |
| 4884 | put_user(sizeof(*attr), &uattr->size); |
| 4885 | ret = -E2BIG; |
| 4886 | goto out; |
| 4887 | } |
| 4888 | |
Li Zefan | 6fb2915 | 2009-10-15 11:21:42 +0800 | [diff] [blame] | 4889 | static int perf_event_set_output(struct perf_event *event, int output_fd) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 4890 | { |
| 4891 | struct perf_event *output_event = NULL; |
| 4892 | struct file *output_file = NULL; |
| 4893 | struct perf_event *old_output; |
| 4894 | int fput_needed = 0; |
| 4895 | int ret = -EINVAL; |
| 4896 | |
| 4897 | if (!output_fd) |
| 4898 | goto set; |
| 4899 | |
| 4900 | output_file = fget_light(output_fd, &fput_needed); |
| 4901 | if (!output_file) |
| 4902 | return -EBADF; |
| 4903 | |
| 4904 | if (output_file->f_op != &perf_fops) |
| 4905 | goto out; |
| 4906 | |
| 4907 | output_event = output_file->private_data; |
| 4908 | |
| 4909 | /* Don't chain output fds */ |
| 4910 | if (output_event->output) |
| 4911 | goto out; |
| 4912 | |
| 4913 | /* Don't set an output fd when we already have an output channel */ |
| 4914 | if (event->data) |
| 4915 | goto out; |
| 4916 | |
| 4917 | atomic_long_inc(&output_file->f_count); |
| 4918 | |
| 4919 | set: |
| 4920 | mutex_lock(&event->mmap_mutex); |
| 4921 | old_output = event->output; |
| 4922 | rcu_assign_pointer(event->output, output_event); |
| 4923 | mutex_unlock(&event->mmap_mutex); |
| 4924 | |
| 4925 | if (old_output) { |
| 4926 | /* |
| 4927 | * we need to make sure no existing perf_output_*() |
| 4928 | * is still referencing this event. |
| 4929 | */ |
| 4930 | synchronize_rcu(); |
| 4931 | fput(old_output->filp); |
| 4932 | } |
| 4933 | |
| 4934 | ret = 0; |
| 4935 | out: |
| 4936 | fput_light(output_file, fput_needed); |
| 4937 | return ret; |
| 4938 | } |
| 4939 | |
| 4940 | /** |
| 4941 | * sys_perf_event_open - open a performance event, associate it to a task/cpu |
| 4942 | * |
| 4943 | * @attr_uptr: event_id type attributes for monitoring/sampling |
| 4944 | * @pid: target pid |
| 4945 | * @cpu: target cpu |
| 4946 | * @group_fd: group leader event fd |
| 4947 | */ |
| 4948 | SYSCALL_DEFINE5(perf_event_open, |
| 4949 | struct perf_event_attr __user *, attr_uptr, |
| 4950 | pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) |
| 4951 | { |
| 4952 | struct perf_event *event, *group_leader; |
| 4953 | struct perf_event_attr attr; |
| 4954 | struct perf_event_context *ctx; |
| 4955 | struct file *event_file = NULL; |
| 4956 | struct file *group_file = NULL; |
| 4957 | int fput_needed = 0; |
| 4958 | int fput_needed2 = 0; |
| 4959 | int err; |
| 4960 | |
| 4961 | /* for future expandability... */ |
| 4962 | if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT)) |
| 4963 | return -EINVAL; |
| 4964 | |
| 4965 | err = perf_copy_attr(attr_uptr, &attr); |
| 4966 | if (err) |
| 4967 | return err; |
| 4968 | |
| 4969 | if (!attr.exclude_kernel) { |
| 4970 | if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) |
| 4971 | return -EACCES; |
| 4972 | } |
| 4973 | |
| 4974 | if (attr.freq) { |
| 4975 | if (attr.sample_freq > sysctl_perf_event_sample_rate) |
| 4976 | return -EINVAL; |
| 4977 | } |
| 4978 | |
| 4979 | /* |
| 4980 | * Get the target context (task or percpu): |
| 4981 | */ |
| 4982 | ctx = find_get_context(pid, cpu); |
| 4983 | if (IS_ERR(ctx)) |
| 4984 | return PTR_ERR(ctx); |
| 4985 | |
| 4986 | /* |
| 4987 | * Look up the group leader (we will attach this event to it): |
| 4988 | */ |
| 4989 | group_leader = NULL; |
| 4990 | if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { |
| 4991 | err = -EINVAL; |
| 4992 | group_file = fget_light(group_fd, &fput_needed); |
| 4993 | if (!group_file) |
| 4994 | goto err_put_context; |
| 4995 | if (group_file->f_op != &perf_fops) |
| 4996 | goto err_put_context; |
| 4997 | |
| 4998 | group_leader = group_file->private_data; |
| 4999 | /* |
| 5000 | * Do not allow a recursive hierarchy (this new sibling |
| 5001 | * becoming part of another group-sibling): |
| 5002 | */ |
| 5003 | if (group_leader->group_leader != group_leader) |
| 5004 | goto err_put_context; |
| 5005 | /* |
| 5006 | * Do not allow to attach to a group in a different |
| 5007 | * task or CPU context: |
| 5008 | */ |
| 5009 | if (group_leader->ctx != ctx) |
| 5010 | goto err_put_context; |
| 5011 | /* |
| 5012 | * Only a group leader can be exclusive or pinned |
| 5013 | */ |
| 5014 | if (attr.exclusive || attr.pinned) |
| 5015 | goto err_put_context; |
| 5016 | } |
| 5017 | |
| 5018 | event = perf_event_alloc(&attr, cpu, ctx, group_leader, |
Frederic Weisbecker | 97eaf53 | 2009-10-18 15:33:50 +0200 | [diff] [blame] | 5019 | NULL, NULL, GFP_KERNEL); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5020 | err = PTR_ERR(event); |
| 5021 | if (IS_ERR(event)) |
| 5022 | goto err_put_context; |
| 5023 | |
Roland Dreier | 628ff7c | 2009-12-18 09:41:24 -0800 | [diff] [blame] | 5024 | err = anon_inode_getfd("[perf_event]", &perf_fops, event, O_RDWR); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5025 | if (err < 0) |
| 5026 | goto err_free_put_context; |
| 5027 | |
| 5028 | event_file = fget_light(err, &fput_needed2); |
| 5029 | if (!event_file) |
| 5030 | goto err_free_put_context; |
| 5031 | |
| 5032 | if (flags & PERF_FLAG_FD_OUTPUT) { |
| 5033 | err = perf_event_set_output(event, group_fd); |
| 5034 | if (err) |
| 5035 | goto err_fput_free_put_context; |
| 5036 | } |
| 5037 | |
| 5038 | event->filp = event_file; |
| 5039 | WARN_ON_ONCE(ctx->parent_ctx); |
| 5040 | mutex_lock(&ctx->mutex); |
| 5041 | perf_install_in_context(ctx, event, cpu); |
| 5042 | ++ctx->generation; |
| 5043 | mutex_unlock(&ctx->mutex); |
| 5044 | |
| 5045 | event->owner = current; |
| 5046 | get_task_struct(current); |
| 5047 | mutex_lock(¤t->perf_event_mutex); |
| 5048 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); |
| 5049 | mutex_unlock(¤t->perf_event_mutex); |
| 5050 | |
| 5051 | err_fput_free_put_context: |
| 5052 | fput_light(event_file, fput_needed2); |
| 5053 | |
| 5054 | err_free_put_context: |
| 5055 | if (err < 0) |
Tejun Heo | 048c852 | 2010-05-01 10:11:35 +0200 | [diff] [blame] | 5056 | free_event(event); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5057 | |
| 5058 | err_put_context: |
| 5059 | if (err < 0) |
| 5060 | put_ctx(ctx); |
| 5061 | |
| 5062 | fput_light(group_file, fput_needed); |
| 5063 | |
| 5064 | return err; |
| 5065 | } |
| 5066 | |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5067 | /** |
| 5068 | * perf_event_create_kernel_counter |
| 5069 | * |
| 5070 | * @attr: attributes of the counter to create |
| 5071 | * @cpu: cpu in which the counter is bound |
| 5072 | * @pid: task to profile |
| 5073 | */ |
| 5074 | struct perf_event * |
| 5075 | perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 5076 | pid_t pid, |
| 5077 | perf_overflow_handler_t overflow_handler) |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5078 | { |
| 5079 | struct perf_event *event; |
| 5080 | struct perf_event_context *ctx; |
| 5081 | int err; |
| 5082 | |
| 5083 | /* |
| 5084 | * Get the target context (task or percpu): |
| 5085 | */ |
| 5086 | |
| 5087 | ctx = find_get_context(pid, cpu); |
Frederic Weisbecker | c6567f6 | 2009-11-26 05:35:41 +0100 | [diff] [blame] | 5088 | if (IS_ERR(ctx)) { |
| 5089 | err = PTR_ERR(ctx); |
| 5090 | goto err_exit; |
| 5091 | } |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5092 | |
| 5093 | event = perf_event_alloc(attr, cpu, ctx, NULL, |
Frederic Weisbecker | b326e95 | 2009-12-05 09:44:31 +0100 | [diff] [blame] | 5094 | NULL, overflow_handler, GFP_KERNEL); |
Frederic Weisbecker | c6567f6 | 2009-11-26 05:35:41 +0100 | [diff] [blame] | 5095 | if (IS_ERR(event)) { |
| 5096 | err = PTR_ERR(event); |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5097 | goto err_put_context; |
Frederic Weisbecker | c6567f6 | 2009-11-26 05:35:41 +0100 | [diff] [blame] | 5098 | } |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5099 | |
| 5100 | event->filp = NULL; |
| 5101 | WARN_ON_ONCE(ctx->parent_ctx); |
| 5102 | mutex_lock(&ctx->mutex); |
| 5103 | perf_install_in_context(ctx, event, cpu); |
| 5104 | ++ctx->generation; |
| 5105 | mutex_unlock(&ctx->mutex); |
| 5106 | |
| 5107 | event->owner = current; |
| 5108 | get_task_struct(current); |
| 5109 | mutex_lock(¤t->perf_event_mutex); |
| 5110 | list_add_tail(&event->owner_entry, ¤t->perf_event_list); |
| 5111 | mutex_unlock(¤t->perf_event_mutex); |
| 5112 | |
| 5113 | return event; |
| 5114 | |
Frederic Weisbecker | c6567f6 | 2009-11-26 05:35:41 +0100 | [diff] [blame] | 5115 | err_put_context: |
| 5116 | put_ctx(ctx); |
| 5117 | err_exit: |
| 5118 | return ERR_PTR(err); |
Arjan van de Ven | fb0459d | 2009-09-25 12:25:56 +0200 | [diff] [blame] | 5119 | } |
| 5120 | EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); |
| 5121 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5122 | /* |
| 5123 | * inherit a event from parent task to child task: |
| 5124 | */ |
| 5125 | static struct perf_event * |
| 5126 | inherit_event(struct perf_event *parent_event, |
| 5127 | struct task_struct *parent, |
| 5128 | struct perf_event_context *parent_ctx, |
| 5129 | struct task_struct *child, |
| 5130 | struct perf_event *group_leader, |
| 5131 | struct perf_event_context *child_ctx) |
| 5132 | { |
| 5133 | struct perf_event *child_event; |
| 5134 | |
| 5135 | /* |
| 5136 | * Instead of creating recursive hierarchies of events, |
| 5137 | * we link inherited events back to the original parent, |
| 5138 | * which has a filp for sure, which we use as the reference |
| 5139 | * count: |
| 5140 | */ |
| 5141 | if (parent_event->parent) |
| 5142 | parent_event = parent_event->parent; |
| 5143 | |
| 5144 | child_event = perf_event_alloc(&parent_event->attr, |
| 5145 | parent_event->cpu, child_ctx, |
| 5146 | group_leader, parent_event, |
Frederic Weisbecker | 97eaf53 | 2009-10-18 15:33:50 +0200 | [diff] [blame] | 5147 | NULL, GFP_KERNEL); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5148 | if (IS_ERR(child_event)) |
| 5149 | return child_event; |
| 5150 | get_ctx(child_ctx); |
| 5151 | |
| 5152 | /* |
| 5153 | * Make the child state follow the state of the parent event, |
| 5154 | * not its attr.disabled bit. We hold the parent's mutex, |
| 5155 | * so we won't race with perf_event_{en, dis}able_family. |
| 5156 | */ |
| 5157 | if (parent_event->state >= PERF_EVENT_STATE_INACTIVE) |
| 5158 | child_event->state = PERF_EVENT_STATE_INACTIVE; |
| 5159 | else |
| 5160 | child_event->state = PERF_EVENT_STATE_OFF; |
| 5161 | |
Peter Zijlstra | 75c9f32 | 2010-01-29 09:04:26 +0100 | [diff] [blame] | 5162 | if (parent_event->attr.freq) { |
| 5163 | u64 sample_period = parent_event->hw.sample_period; |
| 5164 | struct hw_perf_event *hwc = &child_event->hw; |
| 5165 | |
| 5166 | hwc->sample_period = sample_period; |
| 5167 | hwc->last_period = sample_period; |
| 5168 | |
| 5169 | atomic64_set(&hwc->period_left, sample_period); |
| 5170 | } |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5171 | |
Peter Zijlstra | 453f19e | 2009-11-20 22:19:43 +0100 | [diff] [blame] | 5172 | child_event->overflow_handler = parent_event->overflow_handler; |
| 5173 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5174 | /* |
| 5175 | * Link it up in the child's context: |
| 5176 | */ |
| 5177 | add_event_to_ctx(child_event, child_ctx); |
| 5178 | |
| 5179 | /* |
| 5180 | * Get a reference to the parent filp - we will fput it |
| 5181 | * when the child event exits. This is safe to do because |
| 5182 | * we are in the parent and we know that the filp still |
| 5183 | * exists and has a nonzero count: |
| 5184 | */ |
| 5185 | atomic_long_inc(&parent_event->filp->f_count); |
| 5186 | |
| 5187 | /* |
| 5188 | * Link this into the parent event's child list |
| 5189 | */ |
| 5190 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
| 5191 | mutex_lock(&parent_event->child_mutex); |
| 5192 | list_add_tail(&child_event->child_list, &parent_event->child_list); |
| 5193 | mutex_unlock(&parent_event->child_mutex); |
| 5194 | |
| 5195 | return child_event; |
| 5196 | } |
| 5197 | |
| 5198 | static int inherit_group(struct perf_event *parent_event, |
| 5199 | struct task_struct *parent, |
| 5200 | struct perf_event_context *parent_ctx, |
| 5201 | struct task_struct *child, |
| 5202 | struct perf_event_context *child_ctx) |
| 5203 | { |
| 5204 | struct perf_event *leader; |
| 5205 | struct perf_event *sub; |
| 5206 | struct perf_event *child_ctr; |
| 5207 | |
| 5208 | leader = inherit_event(parent_event, parent, parent_ctx, |
| 5209 | child, NULL, child_ctx); |
| 5210 | if (IS_ERR(leader)) |
| 5211 | return PTR_ERR(leader); |
| 5212 | list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { |
| 5213 | child_ctr = inherit_event(sub, parent, parent_ctx, |
| 5214 | child, leader, child_ctx); |
| 5215 | if (IS_ERR(child_ctr)) |
| 5216 | return PTR_ERR(child_ctr); |
| 5217 | } |
| 5218 | return 0; |
| 5219 | } |
| 5220 | |
| 5221 | static void sync_child_event(struct perf_event *child_event, |
| 5222 | struct task_struct *child) |
| 5223 | { |
| 5224 | struct perf_event *parent_event = child_event->parent; |
| 5225 | u64 child_val; |
| 5226 | |
| 5227 | if (child_event->attr.inherit_stat) |
| 5228 | perf_event_read_event(child_event, child); |
| 5229 | |
| 5230 | child_val = atomic64_read(&child_event->count); |
| 5231 | |
| 5232 | /* |
| 5233 | * Add back the child's count to the parent's count: |
| 5234 | */ |
| 5235 | atomic64_add(child_val, &parent_event->count); |
| 5236 | atomic64_add(child_event->total_time_enabled, |
| 5237 | &parent_event->child_total_time_enabled); |
| 5238 | atomic64_add(child_event->total_time_running, |
| 5239 | &parent_event->child_total_time_running); |
| 5240 | |
| 5241 | /* |
| 5242 | * Remove this event from the parent's list |
| 5243 | */ |
| 5244 | WARN_ON_ONCE(parent_event->ctx->parent_ctx); |
| 5245 | mutex_lock(&parent_event->child_mutex); |
| 5246 | list_del_init(&child_event->child_list); |
| 5247 | mutex_unlock(&parent_event->child_mutex); |
| 5248 | |
| 5249 | /* |
| 5250 | * Release the parent event, if this was the last |
| 5251 | * reference to it. |
| 5252 | */ |
| 5253 | fput(parent_event->filp); |
| 5254 | } |
| 5255 | |
| 5256 | static void |
| 5257 | __perf_event_exit_task(struct perf_event *child_event, |
| 5258 | struct perf_event_context *child_ctx, |
| 5259 | struct task_struct *child) |
| 5260 | { |
| 5261 | struct perf_event *parent_event; |
| 5262 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5263 | perf_event_remove_from_context(child_event); |
| 5264 | |
| 5265 | parent_event = child_event->parent; |
| 5266 | /* |
| 5267 | * It can happen that parent exits first, and has events |
| 5268 | * that are still around due to the child reference. These |
| 5269 | * events need to be zapped - but otherwise linger. |
| 5270 | */ |
| 5271 | if (parent_event) { |
| 5272 | sync_child_event(child_event, child); |
| 5273 | free_event(child_event); |
| 5274 | } |
| 5275 | } |
| 5276 | |
| 5277 | /* |
| 5278 | * When a child task exits, feed back event values to parent events. |
| 5279 | */ |
| 5280 | void perf_event_exit_task(struct task_struct *child) |
| 5281 | { |
| 5282 | struct perf_event *child_event, *tmp; |
| 5283 | struct perf_event_context *child_ctx; |
| 5284 | unsigned long flags; |
| 5285 | |
| 5286 | if (likely(!child->perf_event_ctxp)) { |
| 5287 | perf_event_task(child, NULL, 0); |
| 5288 | return; |
| 5289 | } |
| 5290 | |
| 5291 | local_irq_save(flags); |
| 5292 | /* |
| 5293 | * We can't reschedule here because interrupts are disabled, |
| 5294 | * and either child is current or it is a task that can't be |
| 5295 | * scheduled, so we are now safe from rescheduling changing |
| 5296 | * our context. |
| 5297 | */ |
| 5298 | child_ctx = child->perf_event_ctxp; |
| 5299 | __perf_event_task_sched_out(child_ctx); |
| 5300 | |
| 5301 | /* |
| 5302 | * Take the context lock here so that if find_get_context is |
| 5303 | * reading child->perf_event_ctxp, we wait until it has |
| 5304 | * incremented the context's refcount before we do put_ctx below. |
| 5305 | */ |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 5306 | raw_spin_lock(&child_ctx->lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5307 | child->perf_event_ctxp = NULL; |
| 5308 | /* |
| 5309 | * If this context is a clone; unclone it so it can't get |
| 5310 | * swapped to another process while we're removing all |
| 5311 | * the events from it. |
| 5312 | */ |
| 5313 | unclone_ctx(child_ctx); |
Peter Zijlstra | 5e942bb | 2009-11-23 11:37:26 +0100 | [diff] [blame] | 5314 | update_context_time(child_ctx); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 5315 | raw_spin_unlock_irqrestore(&child_ctx->lock, flags); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5316 | |
| 5317 | /* |
| 5318 | * Report the task dead after unscheduling the events so that we |
| 5319 | * won't get any samples after PERF_RECORD_EXIT. We can however still |
| 5320 | * get a few PERF_RECORD_READ events. |
| 5321 | */ |
| 5322 | perf_event_task(child, child_ctx, 0); |
| 5323 | |
| 5324 | /* |
| 5325 | * We can recurse on the same lock type through: |
| 5326 | * |
| 5327 | * __perf_event_exit_task() |
| 5328 | * sync_child_event() |
| 5329 | * fput(parent_event->filp) |
| 5330 | * perf_release() |
| 5331 | * mutex_lock(&ctx->mutex) |
| 5332 | * |
| 5333 | * But since its the parent context it won't be the same instance. |
| 5334 | */ |
Peter Zijlstra | a0507c8 | 2010-05-06 15:42:53 +0200 | [diff] [blame] | 5335 | mutex_lock(&child_ctx->mutex); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5336 | |
| 5337 | again: |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5338 | list_for_each_entry_safe(child_event, tmp, &child_ctx->pinned_groups, |
| 5339 | group_entry) |
| 5340 | __perf_event_exit_task(child_event, child_ctx, child); |
| 5341 | |
| 5342 | list_for_each_entry_safe(child_event, tmp, &child_ctx->flexible_groups, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5343 | group_entry) |
| 5344 | __perf_event_exit_task(child_event, child_ctx, child); |
| 5345 | |
| 5346 | /* |
| 5347 | * If the last event was a group event, it will have appended all |
| 5348 | * its siblings to the list, but we obtained 'tmp' before that which |
| 5349 | * will still point to the list head terminating the iteration. |
| 5350 | */ |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5351 | if (!list_empty(&child_ctx->pinned_groups) || |
| 5352 | !list_empty(&child_ctx->flexible_groups)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5353 | goto again; |
| 5354 | |
| 5355 | mutex_unlock(&child_ctx->mutex); |
| 5356 | |
| 5357 | put_ctx(child_ctx); |
| 5358 | } |
| 5359 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5360 | static void perf_free_event(struct perf_event *event, |
| 5361 | struct perf_event_context *ctx) |
| 5362 | { |
| 5363 | struct perf_event *parent = event->parent; |
| 5364 | |
| 5365 | if (WARN_ON_ONCE(!parent)) |
| 5366 | return; |
| 5367 | |
| 5368 | mutex_lock(&parent->child_mutex); |
| 5369 | list_del_init(&event->child_list); |
| 5370 | mutex_unlock(&parent->child_mutex); |
| 5371 | |
| 5372 | fput(parent->filp); |
| 5373 | |
| 5374 | list_del_event(event, ctx); |
| 5375 | free_event(event); |
| 5376 | } |
| 5377 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5378 | /* |
| 5379 | * free an unexposed, unused context as created by inheritance by |
| 5380 | * init_task below, used by fork() in case of fail. |
| 5381 | */ |
| 5382 | void perf_event_free_task(struct task_struct *task) |
| 5383 | { |
| 5384 | struct perf_event_context *ctx = task->perf_event_ctxp; |
| 5385 | struct perf_event *event, *tmp; |
| 5386 | |
| 5387 | if (!ctx) |
| 5388 | return; |
| 5389 | |
| 5390 | mutex_lock(&ctx->mutex); |
| 5391 | again: |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5392 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, group_entry) |
| 5393 | perf_free_event(event, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5394 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5395 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, |
| 5396 | group_entry) |
| 5397 | perf_free_event(event, ctx); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5398 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5399 | if (!list_empty(&ctx->pinned_groups) || |
| 5400 | !list_empty(&ctx->flexible_groups)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5401 | goto again; |
| 5402 | |
| 5403 | mutex_unlock(&ctx->mutex); |
| 5404 | |
| 5405 | put_ctx(ctx); |
| 5406 | } |
| 5407 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5408 | static int |
| 5409 | inherit_task_group(struct perf_event *event, struct task_struct *parent, |
| 5410 | struct perf_event_context *parent_ctx, |
| 5411 | struct task_struct *child, |
| 5412 | int *inherited_all) |
| 5413 | { |
| 5414 | int ret; |
| 5415 | struct perf_event_context *child_ctx = child->perf_event_ctxp; |
| 5416 | |
| 5417 | if (!event->attr.inherit) { |
| 5418 | *inherited_all = 0; |
| 5419 | return 0; |
| 5420 | } |
| 5421 | |
| 5422 | if (!child_ctx) { |
| 5423 | /* |
| 5424 | * This is executed from the parent task context, so |
| 5425 | * inherit events that have been marked for cloning. |
| 5426 | * First allocate and initialize a context for the |
| 5427 | * child. |
| 5428 | */ |
| 5429 | |
| 5430 | child_ctx = kzalloc(sizeof(struct perf_event_context), |
| 5431 | GFP_KERNEL); |
| 5432 | if (!child_ctx) |
| 5433 | return -ENOMEM; |
| 5434 | |
| 5435 | __perf_event_init_context(child_ctx, child); |
| 5436 | child->perf_event_ctxp = child_ctx; |
| 5437 | get_task_struct(child); |
| 5438 | } |
| 5439 | |
| 5440 | ret = inherit_group(event, parent, parent_ctx, |
| 5441 | child, child_ctx); |
| 5442 | |
| 5443 | if (ret) |
| 5444 | *inherited_all = 0; |
| 5445 | |
| 5446 | return ret; |
| 5447 | } |
| 5448 | |
| 5449 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5450 | /* |
| 5451 | * Initialize the perf_event context in task_struct |
| 5452 | */ |
| 5453 | int perf_event_init_task(struct task_struct *child) |
| 5454 | { |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5455 | struct perf_event_context *child_ctx, *parent_ctx; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5456 | struct perf_event_context *cloned_ctx; |
| 5457 | struct perf_event *event; |
| 5458 | struct task_struct *parent = current; |
| 5459 | int inherited_all = 1; |
| 5460 | int ret = 0; |
| 5461 | |
| 5462 | child->perf_event_ctxp = NULL; |
| 5463 | |
| 5464 | mutex_init(&child->perf_event_mutex); |
| 5465 | INIT_LIST_HEAD(&child->perf_event_list); |
| 5466 | |
| 5467 | if (likely(!parent->perf_event_ctxp)) |
| 5468 | return 0; |
| 5469 | |
| 5470 | /* |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5471 | * If the parent's context is a clone, pin it so it won't get |
| 5472 | * swapped under us. |
| 5473 | */ |
| 5474 | parent_ctx = perf_pin_task_context(parent); |
| 5475 | |
| 5476 | /* |
| 5477 | * No need to check if parent_ctx != NULL here; since we saw |
| 5478 | * it non-NULL earlier, the only reason for it to become NULL |
| 5479 | * is if we exit, and since we're currently in the middle of |
| 5480 | * a fork we can't be exiting at the same time. |
| 5481 | */ |
| 5482 | |
| 5483 | /* |
| 5484 | * Lock the parent list. No need to lock the child - not PID |
| 5485 | * hashed yet and not running, so nobody can access it. |
| 5486 | */ |
| 5487 | mutex_lock(&parent_ctx->mutex); |
| 5488 | |
| 5489 | /* |
| 5490 | * We dont have to disable NMIs - we are only looking at |
| 5491 | * the list, not manipulating it: |
| 5492 | */ |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5493 | list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) { |
| 5494 | ret = inherit_task_group(event, parent, parent_ctx, child, |
| 5495 | &inherited_all); |
| 5496 | if (ret) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5497 | break; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5498 | } |
| 5499 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5500 | list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) { |
| 5501 | ret = inherit_task_group(event, parent, parent_ctx, child, |
| 5502 | &inherited_all); |
| 5503 | if (ret) |
| 5504 | break; |
| 5505 | } |
| 5506 | |
| 5507 | child_ctx = child->perf_event_ctxp; |
| 5508 | |
Peter Zijlstra | 05cbaa2 | 2009-12-30 16:00:35 +0100 | [diff] [blame] | 5509 | if (child_ctx && inherited_all) { |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5510 | /* |
| 5511 | * Mark the child context as a clone of the parent |
| 5512 | * context, or of whatever the parent is a clone of. |
| 5513 | * Note that if the parent is a clone, it could get |
| 5514 | * uncloned at any point, but that doesn't matter |
| 5515 | * because the list of events and the generation |
| 5516 | * count can't have changed since we took the mutex. |
| 5517 | */ |
| 5518 | cloned_ctx = rcu_dereference(parent_ctx->parent_ctx); |
| 5519 | if (cloned_ctx) { |
| 5520 | child_ctx->parent_ctx = cloned_ctx; |
| 5521 | child_ctx->parent_gen = parent_ctx->parent_gen; |
| 5522 | } else { |
| 5523 | child_ctx->parent_ctx = parent_ctx; |
| 5524 | child_ctx->parent_gen = parent_ctx->generation; |
| 5525 | } |
| 5526 | get_ctx(child_ctx->parent_ctx); |
| 5527 | } |
| 5528 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5529 | mutex_unlock(&parent_ctx->mutex); |
| 5530 | |
| 5531 | perf_unpin_context(parent_ctx); |
| 5532 | |
| 5533 | return ret; |
| 5534 | } |
| 5535 | |
Paul Mackerras | 220b140 | 2010-03-10 20:45:52 +1100 | [diff] [blame] | 5536 | static void __init perf_event_init_all_cpus(void) |
| 5537 | { |
| 5538 | int cpu; |
| 5539 | struct perf_cpu_context *cpuctx; |
| 5540 | |
| 5541 | for_each_possible_cpu(cpu) { |
| 5542 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 5543 | mutex_init(&cpuctx->hlist_mutex); |
Paul Mackerras | 220b140 | 2010-03-10 20:45:52 +1100 | [diff] [blame] | 5544 | __perf_event_init_context(&cpuctx->ctx, NULL); |
| 5545 | } |
| 5546 | } |
| 5547 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5548 | static void __cpuinit perf_event_init_cpu(int cpu) |
| 5549 | { |
| 5550 | struct perf_cpu_context *cpuctx; |
| 5551 | |
| 5552 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5553 | |
| 5554 | spin_lock(&perf_resource_lock); |
| 5555 | cpuctx->max_pertask = perf_max_events - perf_reserved_percpu; |
| 5556 | spin_unlock(&perf_resource_lock); |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 5557 | |
| 5558 | mutex_lock(&cpuctx->hlist_mutex); |
| 5559 | if (cpuctx->hlist_refcount > 0) { |
| 5560 | struct swevent_hlist *hlist; |
| 5561 | |
| 5562 | hlist = kzalloc(sizeof(*hlist), GFP_KERNEL); |
| 5563 | WARN_ON_ONCE(!hlist); |
| 5564 | rcu_assign_pointer(cpuctx->swevent_hlist, hlist); |
| 5565 | } |
| 5566 | mutex_unlock(&cpuctx->hlist_mutex); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5567 | } |
| 5568 | |
| 5569 | #ifdef CONFIG_HOTPLUG_CPU |
| 5570 | static void __perf_event_exit_cpu(void *info) |
| 5571 | { |
| 5572 | struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); |
| 5573 | struct perf_event_context *ctx = &cpuctx->ctx; |
| 5574 | struct perf_event *event, *tmp; |
| 5575 | |
Frederic Weisbecker | 889ff01 | 2010-01-09 20:04:47 +0100 | [diff] [blame] | 5576 | list_for_each_entry_safe(event, tmp, &ctx->pinned_groups, group_entry) |
| 5577 | __perf_event_remove_from_context(event); |
| 5578 | list_for_each_entry_safe(event, tmp, &ctx->flexible_groups, group_entry) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5579 | __perf_event_remove_from_context(event); |
| 5580 | } |
| 5581 | static void perf_event_exit_cpu(int cpu) |
| 5582 | { |
| 5583 | struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); |
| 5584 | struct perf_event_context *ctx = &cpuctx->ctx; |
| 5585 | |
Frederic Weisbecker | 76e1d90 | 2010-04-05 15:35:57 +0200 | [diff] [blame] | 5586 | mutex_lock(&cpuctx->hlist_mutex); |
| 5587 | swevent_hlist_release(cpuctx); |
| 5588 | mutex_unlock(&cpuctx->hlist_mutex); |
| 5589 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5590 | mutex_lock(&ctx->mutex); |
| 5591 | smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1); |
| 5592 | mutex_unlock(&ctx->mutex); |
| 5593 | } |
| 5594 | #else |
| 5595 | static inline void perf_event_exit_cpu(int cpu) { } |
| 5596 | #endif |
| 5597 | |
| 5598 | static int __cpuinit |
| 5599 | perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) |
| 5600 | { |
| 5601 | unsigned int cpu = (long)hcpu; |
| 5602 | |
| 5603 | switch (action) { |
| 5604 | |
| 5605 | case CPU_UP_PREPARE: |
| 5606 | case CPU_UP_PREPARE_FROZEN: |
| 5607 | perf_event_init_cpu(cpu); |
| 5608 | break; |
| 5609 | |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5610 | case CPU_DOWN_PREPARE: |
| 5611 | case CPU_DOWN_PREPARE_FROZEN: |
| 5612 | perf_event_exit_cpu(cpu); |
| 5613 | break; |
| 5614 | |
| 5615 | default: |
| 5616 | break; |
| 5617 | } |
| 5618 | |
| 5619 | return NOTIFY_OK; |
| 5620 | } |
| 5621 | |
| 5622 | /* |
| 5623 | * This has to have a higher priority than migration_notifier in sched.c. |
| 5624 | */ |
| 5625 | static struct notifier_block __cpuinitdata perf_cpu_nb = { |
| 5626 | .notifier_call = perf_cpu_notify, |
| 5627 | .priority = 20, |
| 5628 | }; |
| 5629 | |
| 5630 | void __init perf_event_init(void) |
| 5631 | { |
Paul Mackerras | 220b140 | 2010-03-10 20:45:52 +1100 | [diff] [blame] | 5632 | perf_event_init_all_cpus(); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5633 | perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, |
| 5634 | (void *)(long)smp_processor_id()); |
| 5635 | perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, |
| 5636 | (void *)(long)smp_processor_id()); |
| 5637 | register_cpu_notifier(&perf_cpu_nb); |
| 5638 | } |
| 5639 | |
Andi Kleen | c9be0a3 | 2010-01-05 12:47:58 +0100 | [diff] [blame] | 5640 | static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, |
| 5641 | struct sysdev_class_attribute *attr, |
| 5642 | char *buf) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5643 | { |
| 5644 | return sprintf(buf, "%d\n", perf_reserved_percpu); |
| 5645 | } |
| 5646 | |
| 5647 | static ssize_t |
| 5648 | perf_set_reserve_percpu(struct sysdev_class *class, |
Andi Kleen | c9be0a3 | 2010-01-05 12:47:58 +0100 | [diff] [blame] | 5649 | struct sysdev_class_attribute *attr, |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5650 | const char *buf, |
| 5651 | size_t count) |
| 5652 | { |
| 5653 | struct perf_cpu_context *cpuctx; |
| 5654 | unsigned long val; |
| 5655 | int err, cpu, mpt; |
| 5656 | |
| 5657 | err = strict_strtoul(buf, 10, &val); |
| 5658 | if (err) |
| 5659 | return err; |
| 5660 | if (val > perf_max_events) |
| 5661 | return -EINVAL; |
| 5662 | |
| 5663 | spin_lock(&perf_resource_lock); |
| 5664 | perf_reserved_percpu = val; |
| 5665 | for_each_online_cpu(cpu) { |
| 5666 | cpuctx = &per_cpu(perf_cpu_context, cpu); |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 5667 | raw_spin_lock_irq(&cpuctx->ctx.lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5668 | mpt = min(perf_max_events - cpuctx->ctx.nr_events, |
| 5669 | perf_max_events - perf_reserved_percpu); |
| 5670 | cpuctx->max_pertask = mpt; |
Thomas Gleixner | e625cce | 2009-11-17 18:02:06 +0100 | [diff] [blame] | 5671 | raw_spin_unlock_irq(&cpuctx->ctx.lock); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5672 | } |
| 5673 | spin_unlock(&perf_resource_lock); |
| 5674 | |
| 5675 | return count; |
| 5676 | } |
| 5677 | |
Andi Kleen | c9be0a3 | 2010-01-05 12:47:58 +0100 | [diff] [blame] | 5678 | static ssize_t perf_show_overcommit(struct sysdev_class *class, |
| 5679 | struct sysdev_class_attribute *attr, |
| 5680 | char *buf) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5681 | { |
| 5682 | return sprintf(buf, "%d\n", perf_overcommit); |
| 5683 | } |
| 5684 | |
| 5685 | static ssize_t |
Andi Kleen | c9be0a3 | 2010-01-05 12:47:58 +0100 | [diff] [blame] | 5686 | perf_set_overcommit(struct sysdev_class *class, |
| 5687 | struct sysdev_class_attribute *attr, |
| 5688 | const char *buf, size_t count) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 5689 | { |
| 5690 | unsigned long val; |
| 5691 | int err; |
| 5692 | |
| 5693 | err = strict_strtoul(buf, 10, &val); |
| 5694 | if (err) |
| 5695 | return err; |
| 5696 | if (val > 1) |
| 5697 | return -EINVAL; |
| 5698 | |
| 5699 | spin_lock(&perf_resource_lock); |
| 5700 | perf_overcommit = val; |
| 5701 | spin_unlock(&perf_resource_lock); |
| 5702 | |
| 5703 | return count; |
| 5704 | } |
| 5705 | |
| 5706 | static SYSDEV_CLASS_ATTR( |
| 5707 | reserve_percpu, |
| 5708 | 0644, |
| 5709 | perf_show_reserve_percpu, |
| 5710 | perf_set_reserve_percpu |
| 5711 | ); |
| 5712 | |
| 5713 | static SYSDEV_CLASS_ATTR( |
| 5714 | overcommit, |
| 5715 | 0644, |
| 5716 | perf_show_overcommit, |
| 5717 | perf_set_overcommit |
| 5718 | ); |
| 5719 | |
| 5720 | static struct attribute *perfclass_attrs[] = { |
| 5721 | &attr_reserve_percpu.attr, |
| 5722 | &attr_overcommit.attr, |
| 5723 | NULL |
| 5724 | }; |
| 5725 | |
| 5726 | static struct attribute_group perfclass_attr_group = { |
| 5727 | .attrs = perfclass_attrs, |
| 5728 | .name = "perf_events", |
| 5729 | }; |
| 5730 | |
| 5731 | static int __init perf_event_sysfs_init(void) |
| 5732 | { |
| 5733 | return sysfs_create_group(&cpu_sysdev_class.kset.kobj, |
| 5734 | &perfclass_attr_group); |
| 5735 | } |
| 5736 | device_initcall(perf_event_sysfs_init); |