Commit e8da1b18 authored by Nikhil Rao's avatar Nikhil Rao Committed by Ingo Molnar

sched: Add exports tracking cfs bandwidth control statistics

This change introduces statistics exports for the cpu sub-system, these are
added through the use of a stat file similar to that exported by other
subsystems.

The following exports are included:

nr_periods:	number of periods in which execution occurred
nr_throttled:	the number of periods above in which execution was throttle
throttled_time:	cumulative wall-time that any cpus have been throttled for
this group
Signed-off-by: default avatarPaul Turner <pjt@google.com>
Signed-off-by: default avatarNikhil Rao <ncrao@google.com>
Signed-off-by: default avatarBharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: default avatarHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110721184758.198901931@google.comSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d3d9dc33
...@@ -262,6 +262,9 @@ struct cfs_bandwidth { ...@@ -262,6 +262,9 @@ struct cfs_bandwidth {
struct hrtimer period_timer; struct hrtimer period_timer;
struct list_head throttled_cfs_rq; struct list_head throttled_cfs_rq;
/* statistics */
int nr_periods, nr_throttled;
u64 throttled_time;
#endif #endif
}; };
...@@ -402,6 +405,7 @@ struct cfs_rq { ...@@ -402,6 +405,7 @@ struct cfs_rq {
u64 runtime_expires; u64 runtime_expires;
s64 runtime_remaining; s64 runtime_remaining;
u64 throttled_timestamp;
int throttled, throttle_count; int throttled, throttle_count;
struct list_head throttled_list; struct list_head throttled_list;
#endif #endif
...@@ -9397,6 +9401,19 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) ...@@ -9397,6 +9401,19 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret; return ret;
} }
static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
struct cgroup_map_cb *cb)
{
struct task_group *tg = cgroup_tg(cgrp);
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
cb->fill(cb, "nr_periods", cfs_b->nr_periods);
cb->fill(cb, "nr_throttled", cfs_b->nr_throttled);
cb->fill(cb, "throttled_time", cfs_b->throttled_time);
return 0;
}
#endif /* CONFIG_CFS_BANDWIDTH */ #endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */ #endif /* CONFIG_FAIR_GROUP_SCHED */
...@@ -9443,6 +9460,10 @@ static struct cftype cpu_files[] = { ...@@ -9443,6 +9460,10 @@ static struct cftype cpu_files[] = {
.read_u64 = cpu_cfs_period_read_u64, .read_u64 = cpu_cfs_period_read_u64,
.write_u64 = cpu_cfs_period_write_u64, .write_u64 = cpu_cfs_period_write_u64,
}, },
{
.name = "stat",
.read_map = cpu_stats_show,
},
#endif #endif
#ifdef CONFIG_RT_GROUP_SCHED #ifdef CONFIG_RT_GROUP_SCHED
{ {
......
...@@ -1506,6 +1506,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) ...@@ -1506,6 +1506,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
rq->nr_running -= task_delta; rq->nr_running -= task_delta;
cfs_rq->throttled = 1; cfs_rq->throttled = 1;
cfs_rq->throttled_timestamp = rq->clock;
raw_spin_lock(&cfs_b->lock); raw_spin_lock(&cfs_b->lock);
list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
raw_spin_unlock(&cfs_b->lock); raw_spin_unlock(&cfs_b->lock);
...@@ -1523,8 +1524,10 @@ static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) ...@@ -1523,8 +1524,10 @@ static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
cfs_rq->throttled = 0; cfs_rq->throttled = 0;
raw_spin_lock(&cfs_b->lock); raw_spin_lock(&cfs_b->lock);
cfs_b->throttled_time += rq->clock - cfs_rq->throttled_timestamp;
list_del_rcu(&cfs_rq->throttled_list); list_del_rcu(&cfs_rq->throttled_list);
raw_spin_unlock(&cfs_b->lock); raw_spin_unlock(&cfs_b->lock);
cfs_rq->throttled_timestamp = 0;
update_rq_clock(rq); update_rq_clock(rq);
/* update hierarchical throttle state */ /* update hierarchical throttle state */
...@@ -1612,6 +1615,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) ...@@ -1612,6 +1615,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
throttled = !list_empty(&cfs_b->throttled_cfs_rq); throttled = !list_empty(&cfs_b->throttled_cfs_rq);
/* idle depends on !throttled (for the case of a large deficit) */ /* idle depends on !throttled (for the case of a large deficit) */
idle = cfs_b->idle && !throttled; idle = cfs_b->idle && !throttled;
cfs_b->nr_periods += overrun;
/* if we're going inactive then everything else can be deferred */ /* if we're going inactive then everything else can be deferred */
if (idle) if (idle)
...@@ -1625,6 +1629,9 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) ...@@ -1625,6 +1629,9 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
goto out_unlock; goto out_unlock;
} }
/* account preceding periods in which throttling occurred */
cfs_b->nr_throttled += overrun;
/* /*
* There are throttled entities so we must first use the new bandwidth * There are throttled entities so we must first use the new bandwidth
* to unthrottle them before making it generally available. This * to unthrottle them before making it generally available. This
......
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