sched: scheduler debugging, core
scheduler debugging core: implement /proc/sched_debug and
/proc/<PID>/sched files for scheduler debugging.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
new file mode 100644
index 0000000..1baf87c
--- /dev/null
+++ b/kernel/sched_debug.c
@@ -0,0 +1,275 @@
+/*
+ * kernel/time/sched_debug.c
+ *
+ * Print the CFS rbtree
+ *
+ * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/utsname.h>
+
+/*
+ * This allows printing both to /proc/sched_debug and
+ * to the console
+ */
+#define SEQ_printf(m, x...) \
+ do { \
+ if (m) \
+ seq_printf(m, x); \
+ else \
+ printk(x); \
+ } while (0)
+
+static void
+print_task(struct seq_file *m, struct rq *rq, struct task_struct *p, u64 now)
+{
+ if (rq->curr == p)
+ SEQ_printf(m, "R");
+ else
+ SEQ_printf(m, " ");
+
+ SEQ_printf(m, "%15s %5d %15Ld %13Ld %13Ld %9Ld %5d "
+ "%15Ld %15Ld %15Ld %15Ld %15Ld\n",
+ p->comm, p->pid,
+ (long long)p->se.fair_key,
+ (long long)(p->se.fair_key - rq->cfs.fair_clock),
+ (long long)p->se.wait_runtime,
+ (long long)(p->nvcsw + p->nivcsw),
+ p->prio,
+ (long long)p->se.sum_exec_runtime,
+ (long long)p->se.sum_wait_runtime,
+ (long long)p->se.sum_sleep_runtime,
+ (long long)p->se.wait_runtime_overruns,
+ (long long)p->se.wait_runtime_underruns);
+}
+
+static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu, u64 now)
+{
+ struct task_struct *g, *p;
+
+ SEQ_printf(m,
+ "\nrunnable tasks:\n"
+ " task PID tree-key delta waiting"
+ " switches prio"
+ " sum-exec sum-wait sum-sleep"
+ " wait-overrun wait-underrun\n"
+ "------------------------------------------------------------------"
+ "----------------"
+ "------------------------------------------------"
+ "--------------------------------\n");
+
+ read_lock_irq(&tasklist_lock);
+
+ do_each_thread(g, p) {
+ if (!p->se.on_rq || task_cpu(p) != rq_cpu)
+ continue;
+
+ print_task(m, rq, p, now);
+ } while_each_thread(g, p);
+
+ read_unlock_irq(&tasklist_lock);
+}
+
+static void
+print_cfs_rq_runtime_sum(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
+{
+ s64 wait_runtime_rq_sum = 0;
+ struct task_struct *p;
+ struct rb_node *curr;
+ unsigned long flags;
+ struct rq *rq = &per_cpu(runqueues, cpu);
+
+ spin_lock_irqsave(&rq->lock, flags);
+ curr = first_fair(cfs_rq);
+ while (curr) {
+ p = rb_entry(curr, struct task_struct, se.run_node);
+ wait_runtime_rq_sum += p->se.wait_runtime;
+
+ curr = rb_next(curr);
+ }
+ spin_unlock_irqrestore(&rq->lock, flags);
+
+ SEQ_printf(m, " .%-30s: %Ld\n", "wait_runtime_rq_sum",
+ (long long)wait_runtime_rq_sum);
+}
+
+void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq, u64 now)
+{
+ SEQ_printf(m, "\ncfs_rq %p\n", cfs_rq);
+
+#define P(x) \
+ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(cfs_rq->x))
+
+ P(fair_clock);
+ P(exec_clock);
+ P(wait_runtime);
+ P(wait_runtime_overruns);
+ P(wait_runtime_underruns);
+ P(sleeper_bonus);
+#undef P
+
+ print_cfs_rq_runtime_sum(m, cpu, cfs_rq);
+}
+
+static void print_cpu(struct seq_file *m, int cpu, u64 now)
+{
+ struct rq *rq = &per_cpu(runqueues, cpu);
+
+#ifdef CONFIG_X86
+ {
+ unsigned int freq = cpu_khz ? : 1;
+
+ SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
+ cpu, freq / 1000, (freq % 1000));
+ }
+#else
+ SEQ_printf(m, "\ncpu#%d\n", cpu);
+#endif
+
+#define P(x) \
+ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x))
+
+ P(nr_running);
+ SEQ_printf(m, " .%-30s: %lu\n", "load",
+ rq->ls.load.weight);
+ P(ls.delta_fair);
+ P(ls.delta_exec);
+ P(nr_switches);
+ P(nr_load_updates);
+ P(nr_uninterruptible);
+ SEQ_printf(m, " .%-30s: %lu\n", "jiffies", jiffies);
+ P(next_balance);
+ P(curr->pid);
+ P(clock);
+ P(prev_clock_raw);
+ P(clock_warps);
+ P(clock_overflows);
+ P(clock_unstable_events);
+ P(clock_max_delta);
+ P(cpu_load[0]);
+ P(cpu_load[1]);
+ P(cpu_load[2]);
+ P(cpu_load[3]);
+ P(cpu_load[4]);
+#undef P
+
+ print_cfs_stats(m, cpu, now);
+
+ print_rq(m, rq, cpu, now);
+}
+
+static int sched_debug_show(struct seq_file *m, void *v)
+{
+ u64 now = ktime_to_ns(ktime_get());
+ int cpu;
+
+ SEQ_printf(m, "Sched Debug Version: v0.04, cfs-v20, %s %.*s\n",
+ init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+
+ SEQ_printf(m, "now at %Lu nsecs\n", (unsigned long long)now);
+
+ for_each_online_cpu(cpu)
+ print_cpu(m, cpu, now);
+
+ SEQ_printf(m, "\n");
+
+ return 0;
+}
+
+void sysrq_sched_debug_show(void)
+{
+ sched_debug_show(NULL, NULL);
+}
+
+static int sched_debug_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_debug_show, NULL);
+}
+
+static struct file_operations sched_debug_fops = {
+ .open = sched_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init init_sched_debug_procfs(void)
+{
+ struct proc_dir_entry *pe;
+
+ pe = create_proc_entry("sched_debug", 0644, NULL);
+ if (!pe)
+ return -ENOMEM;
+
+ pe->proc_fops = &sched_debug_fops;
+
+ return 0;
+}
+
+__initcall(init_sched_debug_procfs);
+
+void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
+{
+ unsigned long flags;
+ int num_threads = 1;
+
+ rcu_read_lock();
+ if (lock_task_sighand(p, &flags)) {
+ num_threads = atomic_read(&p->signal->count);
+ unlock_task_sighand(p, &flags);
+ }
+ rcu_read_unlock();
+
+ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
+ SEQ_printf(m, "----------------------------------------------\n");
+#define P(F) \
+ SEQ_printf(m, "%-25s:%20Ld\n", #F, (long long)p->F)
+
+ P(se.wait_start);
+ P(se.wait_start_fair);
+ P(se.exec_start);
+ P(se.sleep_start);
+ P(se.sleep_start_fair);
+ P(se.block_start);
+ P(se.sleep_max);
+ P(se.block_max);
+ P(se.exec_max);
+ P(se.wait_max);
+ P(se.wait_runtime);
+ P(se.wait_runtime_overruns);
+ P(se.wait_runtime_underruns);
+ P(se.sum_wait_runtime);
+ P(se.sum_exec_runtime);
+ SEQ_printf(m, "%-25s:%20Ld\n",
+ "nr_switches", (long long)(p->nvcsw + p->nivcsw));
+ P(se.load.weight);
+ P(policy);
+ P(prio);
+#undef P
+
+ {
+ u64 t0, t1;
+
+ t0 = sched_clock();
+ t1 = sched_clock();
+ SEQ_printf(m, "%-25s:%20Ld\n",
+ "clock-delta", (long long)(t1-t0));
+ }
+}
+
+void proc_sched_set_task(struct task_struct *p)
+{
+ p->se.sleep_max = p->se.block_max = p->se.exec_max = p->se.wait_max = 0;
+ p->se.wait_runtime_overruns = p->se.wait_runtime_underruns = 0;
+ p->se.sum_exec_runtime = 0;
+}
