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

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.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d3d9dc33

kernel/sched.c

+21 −0
Original line number Diff line number Diff line
@@ -262,6 +262,9 @@ struct cfs_bandwidth { 
	struct hrtimer period_timer;

	struct list_head throttled_cfs_rq;



	/* statistics */

	int nr_periods, nr_throttled;

	u64 throttled_time;

#endif

};
@@ -402,6 +405,7 @@ struct cfs_rq { 
	u64 runtime_expires;

	s64 runtime_remaining;



	u64 throttled_timestamp;

	int throttled, throttle_count;

	struct list_head throttled_list;

#endif
@@ -9397,6 +9401,19 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) 


	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_FAIR_GROUP_SCHED */
@@ -9443,6 +9460,10 @@ static struct cftype cpu_files[] = { 
		.read_u64 = cpu_cfs_period_read_u64,

		.write_u64 = cpu_cfs_period_write_u64,

	},

	{

		.name = "stat",

		.read_map = cpu_stats_show,

	},

#endif

#ifdef CONFIG_RT_GROUP_SCHED

	{

kernel/sched_fair.c

+7 −0
Original line number Diff line number Diff line
@@ -1506,6 +1506,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) 
		rq->nr_running -= task_delta;



	cfs_rq->throttled = 1;

	cfs_rq->throttled_timestamp = rq->clock;

	raw_spin_lock(&cfs_b->lock);

	list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);

	raw_spin_unlock(&cfs_b->lock);
@@ -1523,8 +1524,10 @@ static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) 


	cfs_rq->throttled = 0;

	raw_spin_lock(&cfs_b->lock);

	cfs_b->throttled_time += rq->clock - cfs_rq->throttled_timestamp;

	list_del_rcu(&cfs_rq->throttled_list);

	raw_spin_unlock(&cfs_b->lock);

	cfs_rq->throttled_timestamp = 0;



	update_rq_clock(rq);

	/* update hierarchical throttle state */
@@ -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);

	/* idle depends on !throttled (for the case of a large deficit) */

	idle = cfs_b->idle && !throttled;

	cfs_b->nr_periods += overrun;



	/* if we're going inactive then everything else can be deferred */

	if (idle)
@@ -1625,6 +1629,9 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) 
		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

	 * to unthrottle them before making it generally available.  This