Commit d02e5ed8 authored Oct 15, 2007 by Dmitry Adamushko Committed by Ingo Molnar Oct 15, 2007

sched: sched_setscheduler() fix



Fix a problem in the 'sched-group' patch for !CONFIG_FAIR_GROUP_SCHED.

description:

sched_setscheduler()
{
...
if (task_running()) p->sched_class->put_prev_entity();

[ this one sets up cfs_rq->curr to NULL ]

...

if (task_running) p->sched_class->set_curr_task();

[ and this one is a _NOP_ (empty) for !CONFIG_FAIR_GROUP_SCHED ]

As a result, the task continues to run with cfs_rq->curr == NULL... no 
crashes (due to checks for !NULL in place) but e.g. update_curr() 
effectively becomes a NOP... i.e. runtime statistics for this task is 
not accounted untill it's rescheduled anew.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

parent 29f59db3

kernel/sched_fair.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -984,6 +984,10 @@ static void set_curr_task_fair(struct rq *rq)
		#else
		static void set_curr_task_fair(struct rq *rq)
		{
		struct sched_entity *se = &rq->curr->se;
		struct cfs_rq *cfs_rq = cfs_rq_of(se);

		cfs_rq->curr = se;
		}
		#endif

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