Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits)
sched: Remove forced2_migrations stats
sched: Fix memory leak in two error corner cases
sched: Fix build warning in get_update_sysctl_factor()
sched: Update normalized values on user updates via proc
sched: Make tunable scaling style configurable
sched: Fix missing sched tunable recalculation on cpu add/remove
sched: Fix task priority bug
sched: cgroup: Implement different treatment for idle shares
sched: Remove unnecessary RCU exclusion
sched: Discard some old bits
sched: Clean up check_preempt_wakeup()
sched: Move update_curr() in check_preempt_wakeup() to avoid redundant call
sched: Sanitize fork() handling
sched: Clean up ttwu() rq locking
sched: Remove rq->clock coupling from set_task_cpu()
sched: Consolidate select_task_rq() callers
sched: Remove sysctl.sched_features
sched: Protect sched_rr_get_param() access to task->sched_class
sched: Protect task->cpus_allowed access in sched_getaffinity()
sched: Fix balance vs hotplug race
...
Fixed up conflicts in kernel/sysctl.c (due to sysctl cleanup)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 789cf5f..d77b547 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -84,6 +84,7 @@
#define num_online_cpus() cpumask_weight(cpu_online_mask)
#define num_possible_cpus() cpumask_weight(cpu_possible_mask)
#define num_present_cpus() cpumask_weight(cpu_present_mask)
+#define num_active_cpus() cpumask_weight(cpu_active_mask)
#define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask)
#define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask)
#define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask)
@@ -92,6 +93,7 @@
#define num_online_cpus() 1
#define num_possible_cpus() 1
#define num_present_cpus() 1
+#define num_active_cpus() 1
#define cpu_online(cpu) ((cpu) == 0)
#define cpu_possible(cpu) ((cpu) == 0)
#define cpu_present(cpu) ((cpu) == 0)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3f4fa73..294eb2f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1102,7 +1102,7 @@
void (*set_curr_task) (struct rq *rq);
void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
- void (*task_new) (struct rq *rq, struct task_struct *p);
+ void (*task_fork) (struct task_struct *p);
void (*switched_from) (struct rq *this_rq, struct task_struct *task,
int running);
@@ -1111,7 +1111,8 @@
void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
int oldprio, int running);
- unsigned int (*get_rr_interval) (struct task_struct *task);
+ unsigned int (*get_rr_interval) (struct rq *rq,
+ struct task_struct *task);
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*moved_group) (struct task_struct *p);
@@ -1151,8 +1152,6 @@
u64 start_runtime;
u64 avg_wakeup;
- u64 avg_running;
-
#ifdef CONFIG_SCHEDSTATS
u64 wait_start;
u64 wait_max;
@@ -1175,7 +1174,6 @@
u64 nr_failed_migrations_running;
u64 nr_failed_migrations_hot;
u64 nr_forced_migrations;
- u64 nr_forced2_migrations;
u64 nr_wakeups;
u64 nr_wakeups_sync;
@@ -1904,14 +1902,22 @@
extern unsigned int sysctl_sched_shares_ratelimit;
extern unsigned int sysctl_sched_shares_thresh;
extern unsigned int sysctl_sched_child_runs_first;
+
+enum sched_tunable_scaling {
+ SCHED_TUNABLESCALING_NONE,
+ SCHED_TUNABLESCALING_LOG,
+ SCHED_TUNABLESCALING_LINEAR,
+ SCHED_TUNABLESCALING_END,
+};
+extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
+
#ifdef CONFIG_SCHED_DEBUG
-extern unsigned int sysctl_sched_features;
extern unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_nr_migrate;
extern unsigned int sysctl_sched_time_avg;
extern unsigned int sysctl_timer_migration;
-int sched_nr_latency_handler(struct ctl_table *table, int write,
+int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length,
loff_t *ppos);
#endif
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7c4e271..291ac58 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -212,6 +212,8 @@
err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
hcpu, -1, &nr_calls);
if (err == NOTIFY_BAD) {
+ set_cpu_active(cpu, true);
+
nr_calls--;
__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
hcpu, nr_calls, NULL);
@@ -223,11 +225,11 @@
/* Ensure that we are not runnable on dying cpu */
cpumask_copy(old_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current,
- cpumask_of(cpumask_any_but(cpu_online_mask, cpu)));
+ set_cpus_allowed_ptr(current, cpu_active_mask);
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
+ set_cpu_active(cpu, true);
/* CPU didn't die: tell everyone. Can't complain. */
if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
hcpu) == NOTIFY_BAD)
@@ -292,9 +294,6 @@
err = _cpu_down(cpu, 0);
- if (cpu_online(cpu))
- set_cpu_active(cpu, true);
-
out:
cpu_maps_update_done();
stop_machine_destroy();
@@ -387,6 +386,15 @@
* with the userspace trying to use the CPU hotplug at the same time
*/
cpumask_clear(frozen_cpus);
+
+ for_each_online_cpu(cpu) {
+ if (cpu == first_cpu)
+ continue;
+ set_cpu_active(cpu, false);
+ }
+
+ synchronize_sched();
+
printk("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 3cf2183..ba401fa 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -737,7 +737,7 @@
{
}
-static int generate_sched_domains(struct cpumask **domains,
+static int generate_sched_domains(cpumask_var_t **domains,
struct sched_domain_attr **attributes)
{
*domains = NULL;
@@ -872,7 +872,7 @@
if (retval < 0)
return retval;
- if (!cpumask_subset(trialcs->cpus_allowed, cpu_online_mask))
+ if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask))
return -EINVAL;
}
retval = validate_change(cs, trialcs);
@@ -2010,7 +2010,7 @@
}
/* Continue past cpusets with all cpus, mems online */
- if (cpumask_subset(cp->cpus_allowed, cpu_online_mask) &&
+ if (cpumask_subset(cp->cpus_allowed, cpu_active_mask) &&
nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
continue;
@@ -2019,7 +2019,7 @@
/* Remove offline cpus and mems from this cpuset. */
mutex_lock(&callback_mutex);
cpumask_and(cp->cpus_allowed, cp->cpus_allowed,
- cpu_online_mask);
+ cpu_active_mask);
nodes_and(cp->mems_allowed, cp->mems_allowed,
node_states[N_HIGH_MEMORY]);
mutex_unlock(&callback_mutex);
@@ -2057,8 +2057,10 @@
switch (phase) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
break;
default:
@@ -2067,7 +2069,7 @@
cgroup_lock();
mutex_lock(&callback_mutex);
- cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask);
+ cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
mutex_unlock(&callback_mutex);
scan_for_empty_cpusets(&top_cpuset);
ndoms = generate_sched_domains(&doms, &attr);
@@ -2114,7 +2116,7 @@
void __init cpuset_init_smp(void)
{
- cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask);
+ cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
hotcpu_notifier(cpuset_track_online_cpus, 0);
diff --git a/kernel/sched.c b/kernel/sched.c
index e7f2cfa..ff39cad 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -814,6 +814,7 @@
* default: 0.25ms
*/
unsigned int sysctl_sched_shares_ratelimit = 250000;
+unsigned int normalized_sysctl_sched_shares_ratelimit = 250000;
/*
* Inject some fuzzyness into changing the per-cpu group shares
@@ -1614,7 +1615,7 @@
*/
static int tg_shares_up(struct task_group *tg, void *data)
{
- unsigned long weight, rq_weight = 0, shares = 0;
+ unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
unsigned long *usd_rq_weight;
struct sched_domain *sd = data;
unsigned long flags;
@@ -1630,6 +1631,7 @@
weight = tg->cfs_rq[i]->load.weight;
usd_rq_weight[i] = weight;
+ rq_weight += weight;
/*
* If there are currently no tasks on the cpu pretend there
* is one of average load so that when a new task gets to
@@ -1638,10 +1640,13 @@
if (!weight)
weight = NICE_0_LOAD;
- rq_weight += weight;
+ sum_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
+ if (!rq_weight)
+ rq_weight = sum_weight;
+
if ((!shares && rq_weight) || shares > tg->shares)
shares = tg->shares;
@@ -1810,6 +1815,22 @@
#endif
static void calc_load_account_active(struct rq *this_rq);
+static void update_sysctl(void);
+static int get_update_sysctl_factor(void);
+
+static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
+{
+ set_task_rq(p, cpu);
+#ifdef CONFIG_SMP
+ /*
+ * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
+ * successfuly executed on another CPU. We must ensure that updates of
+ * per-task data have been completed by this moment.
+ */
+ smp_wmb();
+ task_thread_info(p)->cpu = cpu;
+#endif
+}
#include "sched_stats.h"
#include "sched_idletask.c"
@@ -1967,20 +1988,6 @@
return cpu_curr(task_cpu(p)) == p;
}
-static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
-{
- set_task_rq(p, cpu);
-#ifdef CONFIG_SMP
- /*
- * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
- * successfuly executed on another CPU. We must ensure that updates of
- * per-task data have been completed by this moment.
- */
- smp_wmb();
- task_thread_info(p)->cpu = cpu;
-#endif
-}
-
static inline void check_class_changed(struct rq *rq, struct task_struct *p,
const struct sched_class *prev_class,
int oldprio, int running)
@@ -2060,29 +2067,13 @@
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
int old_cpu = task_cpu(p);
- struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
struct cfs_rq *old_cfsrq = task_cfs_rq(p),
*new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
- u64 clock_offset;
-
- clock_offset = old_rq->clock - new_rq->clock;
trace_sched_migrate_task(p, new_cpu);
-#ifdef CONFIG_SCHEDSTATS
- if (p->se.wait_start)
- p->se.wait_start -= clock_offset;
- if (p->se.sleep_start)
- p->se.sleep_start -= clock_offset;
- if (p->se.block_start)
- p->se.block_start -= clock_offset;
-#endif
if (old_cpu != new_cpu) {
p->se.nr_migrations++;
-#ifdef CONFIG_SCHEDSTATS
- if (task_hot(p, old_rq->clock, NULL))
- schedstat_inc(p, se.nr_forced2_migrations);
-#endif
perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
1, 1, NULL, 0);
}
@@ -2323,6 +2314,14 @@
preempt_enable();
}
+#ifdef CONFIG_SMP
+static inline
+int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+{
+ return p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+}
+#endif
+
/***
* try_to_wake_up - wake up a thread
* @p: the to-be-woken-up thread
@@ -2374,17 +2373,14 @@
if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
p->state = TASK_WAKING;
- task_rq_unlock(rq, &flags);
+ __task_rq_unlock(rq);
- cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
- if (cpu != orig_cpu) {
- local_irq_save(flags);
- rq = cpu_rq(cpu);
- update_rq_clock(rq);
+ cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+ if (cpu != orig_cpu)
set_task_cpu(p, cpu);
- local_irq_restore(flags);
- }
- rq = task_rq_lock(p, &flags);
+
+ rq = __task_rq_lock(p);
+ update_rq_clock(rq);
WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);
@@ -2499,7 +2495,6 @@
p->se.avg_overlap = 0;
p->se.start_runtime = 0;
p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
- p->se.avg_running = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
@@ -2521,7 +2516,6 @@
p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0;
- p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0;
@@ -2558,7 +2552,6 @@
void sched_fork(struct task_struct *p, int clone_flags)
{
int cpu = get_cpu();
- unsigned long flags;
__sched_fork(p);
@@ -2592,13 +2585,13 @@
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
+ if (p->sched_class->task_fork)
+ p->sched_class->task_fork(p);
+
#ifdef CONFIG_SMP
- cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
+ cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
#endif
- local_irq_save(flags);
- update_rq_clock(cpu_rq(cpu));
set_task_cpu(p, cpu);
- local_irq_restore(flags);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
@@ -2631,17 +2624,7 @@
rq = task_rq_lock(p, &flags);
BUG_ON(p->state != TASK_RUNNING);
update_rq_clock(rq);
-
- if (!p->sched_class->task_new || !current->se.on_rq) {
- activate_task(rq, p, 0);
- } else {
- /*
- * Let the scheduling class do new task startup
- * management (if any):
- */
- p->sched_class->task_new(rq, p);
- inc_nr_running(rq);
- }
+ activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
@@ -3156,7 +3139,7 @@
void sched_exec(void)
{
int new_cpu, this_cpu = get_cpu();
- new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0);
+ new_cpu = select_task_rq(current, SD_BALANCE_EXEC, 0);
put_cpu();
if (new_cpu != this_cpu)
sched_migrate_task(current, new_cpu);
@@ -3172,10 +3155,6 @@
deactivate_task(src_rq, p, 0);
set_task_cpu(p, this_cpu);
activate_task(this_rq, p, 0);
- /*
- * Note that idle threads have a prio of MAX_PRIO, for this test
- * to be always true for them.
- */
check_preempt_curr(this_rq, p, 0);
}
@@ -4134,7 +4113,7 @@
unsigned long flags;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
- cpumask_copy(cpus, cpu_online_mask);
+ cpumask_copy(cpus, cpu_active_mask);
/*
* When power savings policy is enabled for the parent domain, idle
@@ -4297,7 +4276,7 @@
int all_pinned = 0;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
- cpumask_copy(cpus, cpu_online_mask);
+ cpumask_copy(cpus, cpu_active_mask);
/*
* When power savings policy is enabled for the parent domain, idle
@@ -4694,7 +4673,7 @@
cpumask_set_cpu(cpu, nohz.cpu_mask);
/* time for ilb owner also to sleep */
- if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
+ if (cpumask_weight(nohz.cpu_mask) == num_active_cpus()) {
if (atomic_read(&nohz.load_balancer) == cpu)
atomic_set(&nohz.load_balancer, -1);
return 0;
@@ -5396,13 +5375,14 @@
#endif
}
-static void put_prev_task(struct rq *rq, struct task_struct *p)
+static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
- u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime;
+ if (prev->state == TASK_RUNNING) {
+ u64 runtime = prev->se.sum_exec_runtime;
- update_avg(&p->se.avg_running, runtime);
+ runtime -= prev->se.prev_sum_exec_runtime;
+ runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
- if (p->state == TASK_RUNNING) {
/*
* In order to avoid avg_overlap growing stale when we are
* indeed overlapping and hence not getting put to sleep, grow
@@ -5412,12 +5392,9 @@
* correlates to the amount of cache footprint a task can
* build up.
*/
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
- update_avg(&p->se.avg_overlap, runtime);
- } else {
- update_avg(&p->se.avg_running, 0);
+ update_avg(&prev->se.avg_overlap, runtime);
}
- p->sched_class->put_prev_task(rq, p);
+ prev->sched_class->put_prev_task(rq, prev);
}
/*
@@ -6631,6 +6608,8 @@
long sched_getaffinity(pid_t pid, struct cpumask *mask)
{
struct task_struct *p;
+ unsigned long flags;
+ struct rq *rq;
int retval;
get_online_cpus();
@@ -6645,7 +6624,9 @@
if (retval)
goto out_unlock;
+ rq = task_rq_lock(p, &flags);
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+ task_rq_unlock(rq, &flags);
out_unlock:
read_unlock(&tasklist_lock);
@@ -6883,6 +6864,8 @@
{
struct task_struct *p;
unsigned int time_slice;
+ unsigned long flags;
+ struct rq *rq;
int retval;
struct timespec t;
@@ -6899,7 +6882,9 @@
if (retval)
goto out_unlock;
- time_slice = p->sched_class->get_rr_interval(p);
+ rq = task_rq_lock(p, &flags);
+ time_slice = p->sched_class->get_rr_interval(rq, p);
+ task_rq_unlock(rq, &flags);
read_unlock(&tasklist_lock);
jiffies_to_timespec(time_slice, &t);
@@ -7000,7 +6985,6 @@
__sched_fork(idle);
idle->se.exec_start = sched_clock();
- idle->prio = idle->normal_prio = MAX_PRIO;
cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
__set_task_cpu(idle, cpu);
@@ -7041,22 +7025,43 @@
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
+static int get_update_sysctl_factor(void)
+{
+ unsigned int cpus = min_t(int, num_online_cpus(), 8);
+ unsigned int factor;
+
+ switch (sysctl_sched_tunable_scaling) {
+ case SCHED_TUNABLESCALING_NONE:
+ factor = 1;
+ break;
+ case SCHED_TUNABLESCALING_LINEAR:
+ factor = cpus;
+ break;
+ case SCHED_TUNABLESCALING_LOG:
+ default:
+ factor = 1 + ilog2(cpus);
+ break;
+ }
+
+ return factor;
+}
+
+static void update_sysctl(void)
+{
+ unsigned int factor = get_update_sysctl_factor();
+
+#define SET_SYSCTL(name) \
+ (sysctl_##name = (factor) * normalized_sysctl_##name)
+ SET_SYSCTL(sched_min_granularity);
+ SET_SYSCTL(sched_latency);
+ SET_SYSCTL(sched_wakeup_granularity);
+ SET_SYSCTL(sched_shares_ratelimit);
+#undef SET_SYSCTL
+}
+
static inline void sched_init_granularity(void)
{
- unsigned int factor = 1 + ilog2(num_online_cpus());
- const unsigned long limit = 200000000;
-
- sysctl_sched_min_granularity *= factor;
- if (sysctl_sched_min_granularity > limit)
- sysctl_sched_min_granularity = limit;
-
- sysctl_sched_latency *= factor;
- if (sysctl_sched_latency > limit)
- sysctl_sched_latency = limit;
-
- sysctl_sched_wakeup_granularity *= factor;
-
- sysctl_sched_shares_ratelimit *= factor;
+ update_sysctl();
}
#ifdef CONFIG_SMP
@@ -7093,7 +7098,7 @@
int ret = 0;
rq = task_rq_lock(p, &flags);
- if (!cpumask_intersects(new_mask, cpu_online_mask)) {
+ if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL;
goto out;
}
@@ -7115,7 +7120,7 @@
if (cpumask_test_cpu(task_cpu(p), new_mask))
goto out;
- if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) {
+ if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) {
/* Need help from migration thread: drop lock and wait. */
struct task_struct *mt = rq->migration_thread;
@@ -7269,19 +7274,19 @@
again:
/* Look for allowed, online CPU in same node. */
- for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask)
+ for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
goto move;
/* Any allowed, online CPU? */
- dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask);
+ dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
if (dest_cpu < nr_cpu_ids)
goto move;
/* No more Mr. Nice Guy. */
if (dest_cpu >= nr_cpu_ids) {
cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
- dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed);
+ dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
/*
* Don't tell them about moving exiting tasks or
@@ -7310,7 +7315,7 @@
*/
static void migrate_nr_uninterruptible(struct rq *rq_src)
{
- struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask));
+ struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
unsigned long flags;
local_irq_save(flags);
@@ -7563,7 +7568,7 @@
static struct ctl_table_header *sd_sysctl_header;
static void register_sched_domain_sysctl(void)
{
- int i, cpu_num = num_online_cpus();
+ int i, cpu_num = num_possible_cpus();
struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
char buf[32];
@@ -7573,7 +7578,7 @@
if (entry == NULL)
return;
- for_each_online_cpu(i) {
+ for_each_possible_cpu(i) {
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
entry->mode = 0555;
@@ -7703,7 +7708,6 @@
spin_lock_irq(&rq->lock);
update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
- rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
@@ -9099,7 +9103,7 @@
if (doms_new == NULL) {
ndoms_cur = 0;
doms_new = &fallback_doms;
- cpumask_andnot(doms_new[0], cpu_online_mask, cpu_isolated_map);
+ cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
WARN_ON_ONCE(dattr_new);
}
@@ -9230,8 +9234,10 @@
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
partition_sched_domains(1, NULL, NULL);
return NOTIFY_OK;
@@ -9278,7 +9284,7 @@
#endif
get_online_cpus();
mutex_lock(&sched_domains_mutex);
- arch_init_sched_domains(cpu_online_mask);
+ arch_init_sched_domains(cpu_active_mask);
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
@@ -9842,13 +9848,15 @@
se = kzalloc_node(sizeof(struct sched_entity),
GFP_KERNEL, cpu_to_node(i));
if (!se)
- goto err;
+ goto err_free_rq;
init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
}
return 1;
+ err_free_rq:
+ kfree(cfs_rq);
err:
return 0;
}
@@ -9930,13 +9938,15 @@
rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
GFP_KERNEL, cpu_to_node(i));
if (!rt_se)
- goto err;
+ goto err_free_rq;
init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
}
return 1;
+ err_free_rq:
+ kfree(rt_rq);
err:
return 0;
}
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 6988cf0..5ae24fc 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -309,6 +309,12 @@
print_rq(m, rq, cpu);
}
+static const char *sched_tunable_scaling_names[] = {
+ "none",
+ "logaritmic",
+ "linear"
+};
+
static int sched_debug_show(struct seq_file *m, void *v)
{
u64 now = ktime_to_ns(ktime_get());
@@ -334,6 +340,10 @@
#undef PN
#undef P
+ SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
+ sysctl_sched_tunable_scaling,
+ sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
+
for_each_online_cpu(cpu)
print_cpu(m, cpu);
@@ -399,7 +409,6 @@
PN(se.sum_exec_runtime);
PN(se.avg_overlap);
PN(se.avg_wakeup);
- PN(se.avg_running);
nr_switches = p->nvcsw + p->nivcsw;
@@ -423,7 +432,6 @@
P(se.nr_failed_migrations_running);
P(se.nr_failed_migrations_hot);
P(se.nr_forced_migrations);
- P(se.nr_forced2_migrations);
P(se.nr_wakeups);
P(se.nr_wakeups_sync);
P(se.nr_wakeups_migrate);
@@ -499,7 +507,6 @@
p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0;
- p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0;
p->se.nr_wakeups_migrate = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f61837a..804a411 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -21,6 +21,7 @@
*/
#include <linux/latencytop.h>
+#include <linux/sched.h>
/*
* Targeted preemption latency for CPU-bound tasks:
@@ -35,12 +36,26 @@
* run vmstat and monitor the context-switches (cs) field)
*/
unsigned int sysctl_sched_latency = 5000000ULL;
+unsigned int normalized_sysctl_sched_latency = 5000000ULL;
+
+/*
+ * The initial- and re-scaling of tunables is configurable
+ * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
+ *
+ * Options are:
+ * SCHED_TUNABLESCALING_NONE - unscaled, always *1
+ * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
+ * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
+ */
+enum sched_tunable_scaling sysctl_sched_tunable_scaling
+ = SCHED_TUNABLESCALING_LOG;
/*
* Minimal preemption granularity for CPU-bound tasks:
* (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
unsigned int sysctl_sched_min_granularity = 1000000ULL;
+unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL;
/*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity
@@ -70,6 +85,7 @@
* have immediate wakeup/sleep latencies.
*/
unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
+unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -383,11 +399,12 @@
*/
#ifdef CONFIG_SCHED_DEBUG
-int sched_nr_latency_handler(struct ctl_table *table, int write,
+int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ int factor = get_update_sysctl_factor();
if (ret || !write)
return ret;
@@ -395,6 +412,14 @@
sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
sysctl_sched_min_granularity);
+#define WRT_SYSCTL(name) \
+ (normalized_sysctl_##name = sysctl_##name / (factor))
+ WRT_SYSCTL(sched_min_granularity);
+ WRT_SYSCTL(sched_latency);
+ WRT_SYSCTL(sched_wakeup_granularity);
+ WRT_SYSCTL(sched_shares_ratelimit);
+#undef WRT_SYSCTL
+
return 0;
}
#endif
@@ -1403,7 +1428,6 @@
new_cpu = prev_cpu;
}
- rcu_read_lock();
for_each_domain(cpu, tmp) {
/*
* If power savings logic is enabled for a domain, see if we
@@ -1484,10 +1508,8 @@
update_shares(tmp);
}
- if (affine_sd && wake_affine(affine_sd, p, sync)) {
- new_cpu = cpu;
- goto out;
- }
+ if (affine_sd && wake_affine(affine_sd, p, sync))
+ return cpu;
while (sd) {
int load_idx = sd->forkexec_idx;
@@ -1528,8 +1550,6 @@
/* while loop will break here if sd == NULL */
}
-out:
- rcu_read_unlock();
return new_cpu;
}
#endif /* CONFIG_SMP */
@@ -1651,12 +1671,8 @@
int sync = wake_flags & WF_SYNC;
int scale = cfs_rq->nr_running >= sched_nr_latency;
- update_curr(cfs_rq);
-
- if (unlikely(rt_prio(p->prio))) {
- resched_task(curr);
- return;
- }
+ if (unlikely(rt_prio(p->prio)))
+ goto preempt;
if (unlikely(p->sched_class != &fair_sched_class))
return;
@@ -1682,50 +1698,44 @@
return;
/* Idle tasks are by definition preempted by everybody. */
- if (unlikely(curr->policy == SCHED_IDLE)) {
- resched_task(curr);
- return;
- }
+ if (unlikely(curr->policy == SCHED_IDLE))
+ goto preempt;
- if ((sched_feat(WAKEUP_SYNC) && sync) ||
- (sched_feat(WAKEUP_OVERLAP) &&
- (se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost))) {
- resched_task(curr);
- return;
- }
+ if (sched_feat(WAKEUP_SYNC) && sync)
+ goto preempt;
- if (sched_feat(WAKEUP_RUNNING)) {
- if (pse->avg_running < se->avg_running) {
- set_next_buddy(pse);
- resched_task(curr);
- return;
- }
- }
+ if (sched_feat(WAKEUP_OVERLAP) &&
+ se->avg_overlap < sysctl_sched_migration_cost &&
+ pse->avg_overlap < sysctl_sched_migration_cost)
+ goto preempt;
if (!sched_feat(WAKEUP_PREEMPT))
return;
+ update_curr(cfs_rq);
find_matching_se(&se, &pse);
-
BUG_ON(!pse);
+ if (wakeup_preempt_entity(se, pse) == 1)
+ goto preempt;
- if (wakeup_preempt_entity(se, pse) == 1) {
- resched_task(curr);
- /*
- * Only set the backward buddy when the current task is still
- * on the rq. This can happen when a wakeup gets interleaved
- * with schedule on the ->pre_schedule() or idle_balance()
- * point, either of which can * drop the rq lock.
- *
- * Also, during early boot the idle thread is in the fair class,
- * for obvious reasons its a bad idea to schedule back to it.
- */
- if (unlikely(!se->on_rq || curr == rq->idle))
- return;
- if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
- set_last_buddy(se);
- }
+ return;
+
+preempt:
+ resched_task(curr);
+ /*
+ * Only set the backward buddy when the current task is still
+ * on the rq. This can happen when a wakeup gets interleaved
+ * with schedule on the ->pre_schedule() or idle_balance()
+ * point, either of which can * drop the rq lock.
+ *
+ * Also, during early boot the idle thread is in the fair class,
+ * for obvious reasons its a bad idea to schedule back to it.
+ */
+ if (unlikely(!se->on_rq || curr == rq->idle))
+ return;
+
+ if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
+ set_last_buddy(se);
}
static struct task_struct *pick_next_task_fair(struct rq *rq)
@@ -1905,6 +1915,17 @@
return 0;
}
+
+static void rq_online_fair(struct rq *rq)
+{
+ update_sysctl();
+}
+
+static void rq_offline_fair(struct rq *rq)
+{
+ update_sysctl();
+}
+
#endif /* CONFIG_SMP */
/*
@@ -1922,28 +1943,30 @@
}
/*
- * Share the fairness runtime between parent and child, thus the
- * total amount of pressure for CPU stays equal - new tasks
- * get a chance to run but frequent forkers are not allowed to
- * monopolize the CPU. Note: the parent runqueue is locked,
- * the child is not running yet.
+ * called on fork with the child task as argument from the parent's context
+ * - child not yet on the tasklist
+ * - preemption disabled
*/
-static void task_new_fair(struct rq *rq, struct task_struct *p)
+static void task_fork_fair(struct task_struct *p)
{
- struct cfs_rq *cfs_rq = task_cfs_rq(p);
+ struct cfs_rq *cfs_rq = task_cfs_rq(current);
struct sched_entity *se = &p->se, *curr = cfs_rq->curr;
int this_cpu = smp_processor_id();
+ struct rq *rq = this_rq();
+ unsigned long flags;
- sched_info_queued(p);
+ spin_lock_irqsave(&rq->lock, flags);
+
+ if (unlikely(task_cpu(p) != this_cpu))
+ __set_task_cpu(p, this_cpu);
update_curr(cfs_rq);
+
if (curr)
se->vruntime = curr->vruntime;
place_entity(cfs_rq, se, 1);
- /* 'curr' will be NULL if the child belongs to a different group */
- if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) &&
- curr && entity_before(curr, se)) {
+ if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) {
/*
* Upon rescheduling, sched_class::put_prev_task() will place
* 'current' within the tree based on its new key value.
@@ -1952,7 +1975,7 @@
resched_task(rq->curr);
}
- enqueue_task_fair(rq, p, 0);
+ spin_unlock_irqrestore(&rq->lock, flags);
}
/*
@@ -2014,21 +2037,17 @@
}
#endif
-unsigned int get_rr_interval_fair(struct task_struct *task)
+unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task)
{
struct sched_entity *se = &task->se;
- unsigned long flags;
- struct rq *rq;
unsigned int rr_interval = 0;
/*
* Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
* idle runqueue:
*/
- rq = task_rq_lock(task, &flags);
if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
- task_rq_unlock(rq, &flags);
return rr_interval;
}
@@ -2052,11 +2071,13 @@
.load_balance = load_balance_fair,
.move_one_task = move_one_task_fair,
+ .rq_online = rq_online_fair,
+ .rq_offline = rq_offline_fair,
#endif
.set_curr_task = set_curr_task_fair,
.task_tick = task_tick_fair,
- .task_new = task_new_fair,
+ .task_fork = task_fork_fair,
.prio_changed = prio_changed_fair,
.switched_to = switched_to_fair,
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 0d94083..d5059fd 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -54,11 +54,6 @@
SCHED_FEAT(WAKEUP_OVERLAP, 0)
/*
- * Wakeup preemption towards tasks that run short
- */
-SCHED_FEAT(WAKEUP_RUNNING, 0)
-
-/*
* Use the SYNC wakeup hint, pipes and the likes use this to indicate
* the remote end is likely to consume the data we just wrote, and
* therefore has cache benefit from being placed on the same cpu, see
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index b133a28..33d5384 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -97,7 +97,7 @@
check_preempt_curr(rq, p, 0);
}
-unsigned int get_rr_interval_idle(struct task_struct *task)
+unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
{
return 0;
}
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 5c5fef3..aecbd9c 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1721,7 +1721,7 @@
dequeue_pushable_task(rq, p);
}
-unsigned int get_rr_interval_rt(struct task_struct *task)
+unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
{
/*
* Time slice is 0 for SCHED_FIFO tasks
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9327a26..554ac48 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -244,6 +244,10 @@
static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_wakeup_granularity_ns; /* 0 usecs */
static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
+static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
+static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
+static int min_sched_shares_ratelimit = 100000; /* 100 usec */
+static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
#endif
static struct ctl_table kern_table[] = {
@@ -260,7 +264,7 @@
.data = &sysctl_sched_min_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = sched_nr_latency_handler,
+ .proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
@@ -269,7 +273,7 @@
.data = &sysctl_sched_latency,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = sched_nr_latency_handler,
+ .proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
},
@@ -278,7 +282,7 @@
.data = &sysctl_sched_wakeup_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = proc_dointvec_minmax,
+ .proc_handler = sched_proc_update_handler,
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
},
@@ -287,7 +291,18 @@
.data = &sysctl_sched_shares_ratelimit,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = sched_proc_update_handler,
+ .extra1 = &min_sched_shares_ratelimit,
+ .extra2 = &max_sched_shares_ratelimit,
+ },
+ {
+ .procname = "sched_tunable_scaling",
+ .data = &sysctl_sched_tunable_scaling,
+ .maxlen = sizeof(enum sched_tunable_scaling),
+ .mode = 0644,
+ .proc_handler = sched_proc_update_handler,
+ .extra1 = &min_sched_tunable_scaling,
+ .extra2 = &max_sched_tunable_scaling,
},
{
.procname = "sched_shares_thresh",
@@ -298,13 +313,6 @@
.extra1 = &zero,
},
{
- .procname = "sched_features",
- .data = &sysctl_sched_features,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
.procname = "sched_migration_cost",
.data = &sysctl_sched_migration_cost,
.maxlen = sizeof(unsigned int),
