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authorIngo Molnar <mingo@elte.hu>2007-10-15 17:00:18 +0200
committerIngo Molnar <mingo@elte.hu>2007-10-15 17:00:18 +0200
commitcc367732ff0b1c63d0d7bdd11e6d1661794ef6a3 (patch)
tree27c65e05bf19644224937624ca356c876e6d1318
parent2d92f22784b7b8879ebe3254e44c92cb8792b0dd (diff)
sched: debug, improve migration statistics
add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/sched.h18
-rw-r--r--kernel/sched.c76
-rw-r--r--kernel/sched_debug.c87
3 files changed, 149 insertions, 32 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index fcc9a5ada1a..3a6e05e7771 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -931,6 +931,24 @@ struct sched_entity {
u64 block_max;
u64 exec_max;
u64 slice_max;
+
+ u64 nr_migrations;
+ u64 nr_migrations_cold;
+ u64 nr_failed_migrations_affine;
+ 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;
+ u64 nr_wakeups_migrate;
+ u64 nr_wakeups_local;
+ u64 nr_wakeups_remote;
+ u64 nr_wakeups_affine;
+ u64 nr_wakeups_affine_attempts;
+ u64 nr_wakeups_passive;
+ u64 nr_wakeups_idle;
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched.c b/kernel/sched.c
index 945ab1322e1..3b27c3a553a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1005,6 +1005,23 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
#ifdef CONFIG_SMP
+/*
+ * Is this task likely cache-hot:
+ */
+static inline int
+task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
+{
+ s64 delta;
+
+ if (p->sched_class != &fair_sched_class)
+ return 0;
+
+ delta = now - p->se.exec_start;
+
+ return delta < (s64)sysctl_sched_migration_cost;
+}
+
+
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
int old_cpu = task_cpu(p);
@@ -1022,6 +1039,11 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
+ if (old_cpu != new_cpu) {
+ schedstat_inc(p, se.nr_migrations);
+ if (task_hot(p, old_rq->clock, NULL))
+ schedstat_inc(p, se.nr_forced2_migrations);
+ }
#endif
p->se.vruntime -= old_cfsrq->min_vruntime -
new_cfsrq->min_vruntime;
@@ -1394,8 +1416,13 @@ static int wake_idle(int cpu, struct task_struct *p)
if (sd->flags & SD_WAKE_IDLE) {
cpus_and(tmp, sd->span, p->cpus_allowed);
for_each_cpu_mask(i, tmp) {
- if (idle_cpu(i))
+ if (idle_cpu(i)) {
+ if (i != task_cpu(p)) {
+ schedstat_inc(p,
+ se.nr_wakeups_idle);
+ }
return i;
+ }
}
} else {
break;
@@ -1426,7 +1453,7 @@ static inline int wake_idle(int cpu, struct task_struct *p)
*/
static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
{
- int cpu, this_cpu, success = 0;
+ int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
long old_state;
struct rq *rq;
@@ -1445,6 +1472,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
goto out_running;
cpu = task_cpu(p);
+ orig_cpu = cpu;
this_cpu = smp_processor_id();
#ifdef CONFIG_SMP
@@ -1488,6 +1516,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
unsigned long tl = this_load;
unsigned long tl_per_task;
+ schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
/*
@@ -1507,6 +1536,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
* there is no bad imbalance.
*/
schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(p, se.nr_wakeups_affine);
goto out_set_cpu;
}
}
@@ -1518,6 +1548,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (this_sd->flags & SD_WAKE_BALANCE) {
if (imbalance*this_load <= 100*load) {
schedstat_inc(this_sd, ttwu_move_balance);
+ schedstat_inc(p, se.nr_wakeups_passive);
goto out_set_cpu;
}
}
@@ -1543,6 +1574,15 @@ out_set_cpu:
out_activate:
#endif /* CONFIG_SMP */
+ schedstat_inc(p, se.nr_wakeups);
+ if (sync)
+ schedstat_inc(p, se.nr_wakeups_sync);
+ if (orig_cpu != cpu)
+ schedstat_inc(p, se.nr_wakeups_migrate);
+ if (cpu == this_cpu)
+ schedstat_inc(p, se.nr_wakeups_local);
+ else
+ schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
/*
@@ -2119,22 +2159,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
}
/*
- * Is this task likely cache-hot:
- */
-static inline int
-task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
-{
- s64 delta;
-
- if (p->sched_class != &fair_sched_class)
- return 0;
-
- delta = now - p->se.exec_start;
-
- return delta < (s64)sysctl_sched_migration_cost;
-}
-
-/*
* can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
*/
static
@@ -2148,12 +2172,16 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
*/
- if (!cpu_isset(this_cpu, p->cpus_allowed))
+ if (!cpu_isset(this_cpu, p->cpus_allowed)) {
+ schedstat_inc(p, se.nr_failed_migrations_affine);
return 0;
+ }
*all_pinned = 0;
- if (task_running(rq, p))
+ if (task_running(rq, p)) {
+ schedstat_inc(p, se.nr_failed_migrations_running);
return 0;
+ }
/*
* Aggressive migration if:
@@ -2163,14 +2191,18 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
if (sd->nr_balance_failed > sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
- if (task_hot(p, rq->clock, sd))
+ if (task_hot(p, rq->clock, sd)) {
schedstat_inc(sd, lb_hot_gained[idle]);
+ schedstat_inc(p, se.nr_forced_migrations);
+ }
#endif
return 1;
}
- if (task_hot(p, rq->clock, sd))
+ if (task_hot(p, rq->clock, sd)) {
+ schedstat_inc(p, se.nr_failed_migrations_hot);
return 0;
+ }
return 1;
}
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 75581593741..27e82cbccaa 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -260,6 +260,7 @@ __initcall(init_sched_debug_procfs);
void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
+ unsigned long nr_switches;
unsigned long flags;
int num_threads = 1;
@@ -273,8 +274,12 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
SEQ_printf(m,
"---------------------------------------------------------\n");
+#define __P(F) \
+ SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
#define P(F) \
SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
+#define __PN(F) \
+ SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
@@ -282,6 +287,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.vruntime);
PN(se.sum_exec_runtime);
+ nr_switches = p->nvcsw + p->nivcsw;
+
#ifdef CONFIG_SCHEDSTATS
PN(se.wait_start);
PN(se.sleep_start);
@@ -292,14 +299,55 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.slice_max);
PN(se.wait_max);
P(sched_info.bkl_count);
+ P(se.nr_migrations);
+ P(se.nr_migrations_cold);
+ P(se.nr_failed_migrations_affine);
+ 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);
+ P(se.nr_wakeups_local);
+ P(se.nr_wakeups_remote);
+ P(se.nr_wakeups_affine);
+ P(se.nr_wakeups_affine_attempts);
+ P(se.nr_wakeups_passive);
+ P(se.nr_wakeups_idle);
+
+ {
+ u64 avg_atom, avg_per_cpu;
+
+ avg_atom = p->se.sum_exec_runtime;
+ if (nr_switches)
+ do_div(avg_atom, nr_switches);
+ else
+ avg_atom = -1LL;
+
+ avg_per_cpu = p->se.sum_exec_runtime;
+ if (p->se.nr_migrations)
+ avg_per_cpu = div64_64(avg_per_cpu, p->se.nr_migrations);
+ else
+ avg_per_cpu = -1LL;
+
+ __PN(avg_atom);
+ __PN(avg_per_cpu);
+ }
#endif
+ __P(nr_switches);
SEQ_printf(m, "%-35s:%21Ld\n",
- "nr_switches", (long long)(p->nvcsw + p->nivcsw));
+ "nr_voluntary_switches", (long long)p->nvcsw);
+ SEQ_printf(m, "%-35s:%21Ld\n",
+ "nr_involuntary_switches", (long long)p->nivcsw);
+
P(se.load.weight);
P(policy);
P(prio);
-#undef P
#undef PN
+#undef __PN
+#undef P
+#undef __P
{
u64 t0, t1;
@@ -314,13 +362,32 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
- p->se.sleep_max = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
- p->se.wait_max = 0;
- p->sched_info.bkl_count = 0;
+ p->se.wait_max = 0;
+ p->se.sleep_max = 0;
+ p->se.sum_sleep_runtime = 0;
+ p->se.block_max = 0;
+ p->se.exec_max = 0;
+ p->se.slice_max = 0;
+ p->se.nr_migrations = 0;
+ p->se.nr_migrations_cold = 0;
+ p->se.nr_failed_migrations_affine = 0;
+ 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;
+ p->se.nr_wakeups_local = 0;
+ p->se.nr_wakeups_remote = 0;
+ p->se.nr_wakeups_affine = 0;
+ p->se.nr_wakeups_affine_attempts = 0;
+ p->se.nr_wakeups_passive = 0;
+ p->se.nr_wakeups_idle = 0;
+ p->sched_info.bkl_count = 0;
#endif
- p->se.sum_exec_runtime = 0;
- p->se.prev_sum_exec_runtime = 0;
+ p->se.sum_exec_runtime = 0;
+ p->se.prev_sum_exec_runtime = 0;
+ p->nvcsw = 0;
+ p->nivcsw = 0;
}