Commit 22abdef3 authored Mar 15, 2014 by Kirill Tkhai Committed by Ingo Molnar Apr 18, 2014

sched/rt: Sum number of all children tasks in hierarhy at ->rt_nr_running



{inc,dec}_rt_tasks() used to count entities which are directly queued
on the rt_rq. If an entity was not a task (i.e., it is some queue), its
children were not counted.

There is no problem here, but now we want to count number of all tasks
which are actually queued under the rt_rq in all the hierarchy (except
throttled rt queues).

Empty queues are not able to be queued and all of the places, which
use ->rt_nr_running, just compare it with zero, so we do not break
anything here.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394835289.18748.31.camel@HP-250-G1-Notebook-PC


Cc: linux-kernel@vger.kernel.org
[ Twiddled the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 8698a745

kernel/sched/rt.c

+13 −2

Original line number	Diff line number	Diff line
		@@ -1044,13 +1044,24 @@ void dec_rt_group(struct sched_rt_entity rt_se, struct rt_rq rt_rq) {}

		#endif /* CONFIG_RT_GROUP_SCHED */

		static inline
		unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
		{
		struct rt_rq *group_rq = group_rt_rq(rt_se);

		if (group_rq)
		return group_rq->rt_nr_running;
		else
		return 1;
		}

		static inline
		void inc_rt_tasks(struct sched_rt_entity rt_se, struct rt_rq rt_rq)
		{
		int prio = rt_se_prio(rt_se);

		WARN_ON(!rt_prio(prio));
		rt_rq->rt_nr_running++;
		rt_rq->rt_nr_running += rt_se_nr_running(rt_se);

		inc_rt_prio(rt_rq, prio);
		inc_rt_migration(rt_se, rt_rq);
		@@ -1062,7 +1073,7 @@ void dec_rt_tasks(struct sched_rt_entity rt_se, struct rt_rq rt_rq)
		{
		WARN_ON(!rt_prio(rt_se_prio(rt_se)));
		WARN_ON(!rt_rq->rt_nr_running);
		rt_rq->rt_nr_running--;
		rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);

		dec_rt_prio(rt_rq, rt_se_prio(rt_se));
		dec_rt_migration(rt_se, rt_rq);

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