[PATCH] Group scheduler statistics in one struct

From: Lucas De Marchi
Date: Wed Mar 10 2010 - 21:38:20 EST

Put all statistic fields of sched_entity in one struct, sched_statistics,
and embed it into sched_entity.

This change allows to memset the sched_statistics to 0 when needed (for
instance when forking), avoiding bugs of non initialized fields.

Signed-off-by: Lucas De Marchi <lucas.de.marchi@xxxxxxxxx>
---
include/linux/sched.h | 54 ++++++++++++--------------
kernel/sched.c | 47 ++++------------------
kernel/sched_debug.c | 101 ++++++++++++++++++------------------------------
kernel/sched_fair.c | 65 ++++++++++++++++---------------
kernel/sched_rt.c | 2 +-
5 files changed, 106 insertions(+), 163 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 46c6f8d..909e630 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1073,36 +1073,8 @@ struct load_weight {
unsigned long weight, inv_weight;
};

-/*
- * CFS stats for a schedulable entity (task, task-group etc)
- *
- * Current field usage histogram:
- *
- * 4 se->block_start
- * 4 se->run_node
- * 4 se->sleep_start
- * 6 se->load.weight
- */
-struct sched_entity {
- struct load_weight load; /* for load-balancing */
- struct rb_node run_node;
- struct list_head group_node;
- unsigned int on_rq;
-
- u64 exec_start;
- u64 sum_exec_runtime;
- u64 vruntime;
- u64 prev_sum_exec_runtime;
-
- u64 last_wakeup;
- u64 avg_overlap;
-
- u64 nr_migrations;
-
- u64 start_runtime;
- u64 avg_wakeup;
-
#ifdef CONFIG_SCHEDSTATS
+struct sched_statistics {
u64 wait_start;
u64 wait_max;
u64 wait_count;
@@ -1134,6 +1106,30 @@ struct sched_entity {
u64 nr_wakeups_affine_attempts;
u64 nr_wakeups_passive;
u64 nr_wakeups_idle;
+};
+#endif
+
+struct sched_entity {
+ struct load_weight load; /* for load-balancing */
+ struct rb_node run_node;
+ struct list_head group_node;
+ unsigned int on_rq;
+
+ u64 exec_start;
+ u64 sum_exec_runtime;
+ u64 vruntime;
+ u64 prev_sum_exec_runtime;
+
+ u64 last_wakeup;
+ u64 avg_overlap;
+
+ u64 nr_migrations;
+
+ u64 start_runtime;
+ u64 avg_wakeup;
+
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_statistics statistics;
#endif

#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched.c b/kernel/sched.c
index 150b698..35c6b8a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2437,15 +2437,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,

out_activate:
#endif /* CONFIG_SMP */
- schedstat_inc(p, se.nr_wakeups);
+ schedstat_inc(p, se.statistics.nr_wakeups);
if (wake_flags & WF_SYNC)
- schedstat_inc(p, se.nr_wakeups_sync);
+ schedstat_inc(p, se.statistics.nr_wakeups_sync);
if (orig_cpu != cpu)
- schedstat_inc(p, se.nr_wakeups_migrate);
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
if (cpu == this_cpu)
- schedstat_inc(p, se.nr_wakeups_local);
+ schedstat_inc(p, se.statistics.nr_wakeups_local);
else
- schedstat_inc(p, se.nr_wakeups_remote);
+ schedstat_inc(p, se.statistics.nr_wakeups_remote);
activate_task(rq, p, 1);
success = 1;

@@ -2532,36 +2532,7 @@ static void __sched_fork(struct task_struct *p)
p->se.avg_wakeup = sysctl_sched_wakeup_granularity;

#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.wait_max = 0;
- p->se.wait_count = 0;
- p->se.wait_sum = 0;
-
- p->se.sleep_start = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
-
- p->se.block_start = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 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_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;
-
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif

INIT_LIST_HEAD(&p->rt.run_list);
@@ -7914,9 +7885,9 @@ void normalize_rt_tasks(void)

p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.sleep_start = 0;
- p->se.block_start = 0;
+ p->se.statistics.wait_start = 0;
+ p->se.statistics.sleep_start = 0;
+ p->se.statistics.block_start = 0;
#endif

if (!rt_task(p)) {
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 67f95aa..ad9df44 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -70,16 +70,16 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu,
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
- PN(se->wait_start);
- PN(se->sleep_start);
- PN(se->block_start);
- PN(se->sleep_max);
- PN(se->block_max);
- PN(se->exec_max);
- PN(se->slice_max);
- PN(se->wait_max);
- PN(se->wait_sum);
- P(se->wait_count);
+ PN(se->statistics.wait_start);
+ PN(se->statistics.sleep_start);
+ PN(se->statistics.block_start);
+ PN(se->statistics.sleep_max);
+ PN(se->statistics.block_max);
+ PN(se->statistics.exec_max);
+ PN(se->statistics.slice_max);
+ PN(se->statistics.wait_max);
+ PN(se->statistics.wait_sum);
+ P(se->statistics.wait_count);
#endif
P(se->load.weight);
#undef PN
@@ -104,7 +104,7 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
SPLIT_NS(p->se.vruntime),
SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.sum_sleep_runtime));
+ SPLIT_NS(p->se.statistics.sum_sleep_runtime));
#else
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
@@ -413,34 +413,34 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
nr_switches = p->nvcsw + p->nivcsw;

#ifdef CONFIG_SCHEDSTATS
- PN(se.wait_start);
- PN(se.sleep_start);
- PN(se.block_start);
- PN(se.sleep_max);
- PN(se.block_max);
- PN(se.exec_max);
- PN(se.slice_max);
- PN(se.wait_max);
- PN(se.wait_sum);
- P(se.wait_count);
- PN(se.iowait_sum);
- P(se.iowait_count);
+ PN(se.statistics.wait_start);
+ PN(se.statistics.sleep_start);
+ PN(se.statistics.block_start);
+ PN(se.statistics.sleep_max);
+ PN(se.statistics.block_max);
+ PN(se.statistics.exec_max);
+ PN(se.statistics.slice_max);
+ PN(se.statistics.wait_max);
+ PN(se.statistics.wait_sum);
+ P(se.statistics.wait_count);
+ PN(se.statistics.iowait_sum);
+ P(se.statistics.iowait_count);
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_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);
+ P(se.statistics.nr_migrations_cold);
+ P(se.statistics.nr_failed_migrations_affine);
+ P(se.statistics.nr_failed_migrations_running);
+ P(se.statistics.nr_failed_migrations_hot);
+ P(se.statistics.nr_forced_migrations);
+ P(se.statistics.nr_wakeups);
+ P(se.statistics.nr_wakeups_sync);
+ P(se.statistics.nr_wakeups_migrate);
+ P(se.statistics.nr_wakeups_local);
+ P(se.statistics.nr_wakeups_remote);
+ P(se.statistics.nr_wakeups_affine);
+ P(se.statistics.nr_wakeups_affine_attempts);
+ P(se.statistics.nr_wakeups_passive);
+ P(se.statistics.nr_wakeups_idle);

{
u64 avg_atom, avg_per_cpu;
@@ -491,32 +491,7 @@ 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.wait_max = 0;
- p->se.wait_sum = 0;
- p->se.wait_count = 0;
- p->se.iowait_sum = 0;
- p->se.iowait_count = 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_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;
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 3e1fd96..8ad164b 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -505,7 +505,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
{
unsigned long delta_exec_weighted;

- schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
+ schedstat_set(curr->statistics.exec_max,
+ max((u64)delta_exec, curr->statistics.exec_max));

curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
@@ -548,7 +549,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
static inline void
update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
+ schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
}

/*
@@ -567,18 +568,18 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_max, max(se->wait_max,
- rq_of(cfs_rq)->clock - se->wait_start));
- schedstat_set(se->wait_count, se->wait_count + 1);
- schedstat_set(se->wait_sum, se->wait_sum +
- rq_of(cfs_rq)->clock - se->wait_start);
+ schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+ rq_of(cfs_rq)->clock - se->statistics.wait_start));
+ schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+ schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
trace_sched_stat_wait(task_of(se),
- rq_of(cfs_rq)->clock - se->wait_start);
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
}
#endif
- schedstat_set(se->wait_start, 0);
+ schedstat_set(se->statistics.wait_start, 0);
}

static inline void
@@ -657,39 +658,39 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
if (entity_is_task(se))
tsk = task_of(se);

- if (se->sleep_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
+ if (se->statistics.sleep_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;

if ((s64)delta < 0)
delta = 0;

- if (unlikely(delta > se->sleep_max))
- se->sleep_max = delta;
+ if (unlikely(delta > se->statistics.sleep_max))
+ se->statistics.sleep_max = delta;

- se->sleep_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.sleep_start = 0;
+ se->statistics.sum_sleep_runtime += delta;

if (tsk) {
account_scheduler_latency(tsk, delta >> 10, 1);
trace_sched_stat_sleep(tsk, delta);
}
}
- if (se->block_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->block_start;
+ if (se->statistics.block_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;

if ((s64)delta < 0)
delta = 0;

- if (unlikely(delta > se->block_max))
- se->block_max = delta;
+ if (unlikely(delta > se->statistics.block_max))
+ se->statistics.block_max = delta;

- se->block_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.block_start = 0;
+ se->statistics.sum_sleep_runtime += delta;

if (tsk) {
if (tsk->in_iowait) {
- se->iowait_sum += delta;
- se->iowait_count++;
+ se->statistics.iowait_sum += delta;
+ se->statistics.iowait_count++;
trace_sched_stat_iowait(tsk, delta);
}

@@ -826,9 +827,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
struct task_struct *tsk = task_of(se);

if (tsk->state & TASK_INTERRUPTIBLE)
- se->sleep_start = rq_of(cfs_rq)->clock;
+ se->statistics.sleep_start = rq_of(cfs_rq)->clock;
if (tsk->state & TASK_UNINTERRUPTIBLE)
- se->block_start = rq_of(cfs_rq)->clock;
+ se->statistics.block_start = rq_of(cfs_rq)->clock;
}
#endif
}
@@ -912,7 +913,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* when there are only lesser-weight tasks around):
*/
if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
- se->slice_max = max(se->slice_max,
+ se->statistics.slice_max = max(se->statistics.slice_max,
se->sum_exec_runtime - se->prev_sum_exec_runtime);
}
#endif
@@ -1306,7 +1307,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
if (sync && balanced)
return 1;

- schedstat_inc(p, se.nr_wakeups_affine_attempts);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);

if (balanced ||
@@ -1318,7 +1319,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
* there is no bad imbalance.
*/
schedstat_inc(sd, ttwu_move_affine);
- schedstat_inc(p, se.nr_wakeups_affine);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine);

return 1;
}
@@ -1844,13 +1845,13 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
* 3) are cache-hot on their current CPU.
*/
if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
- schedstat_inc(p, se.nr_failed_migrations_affine);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
return 0;
}
*all_pinned = 0;

if (task_running(rq, p)) {
- schedstat_inc(p, se.nr_failed_migrations_running);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_running);
return 0;
}

@@ -1866,14 +1867,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
#ifdef CONFIG_SCHEDSTATS
if (tsk_cache_hot) {
schedstat_inc(sd, lb_hot_gained[idle]);
- schedstat_inc(p, se.nr_forced_migrations);
+ schedstat_inc(p, se.statistics.nr_forced_migrations);
}
#endif
return 1;
}

if (tsk_cache_hot) {
- schedstat_inc(p, se.nr_failed_migrations_hot);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
return 0;
}
return 1;
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 5a6ed1f..47a121d 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -613,7 +613,7 @@ static void update_curr_rt(struct rq *rq)
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;

- schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
+ schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));

curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
--
1.7.0.2

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