Commit c51b8ab5 authored Nov 06, 2014 by Wanpeng Li Committed by Ingo Molnar Nov 16, 2014

sched/deadline: Fix rq->dl.pushable_tasks bug in push_dl_task()



Do not call dequeue_pushable_dl_task() when failing to push an eligible
task, as it remains pushable, merely not at this particular moment.

Actually the patch is the same behavior as commit 311e800e ("sched,
rt: Fix rq->rt.pushable_tasks bug in push_rt_task()" in -rt side.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1415258564-8573-1-git-send-email-wanpeng.li@linux.intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent cb0b9f24

kernel/sched/deadline.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1328,6 +1328,7 @@ static int push_dl_task(struct rq *rq)
		{
		struct task_struct *next_task;
		struct rq *later_rq;
		int ret = 0;

		if (!rq->dl.overloaded)
		return 0;
		@@ -1373,7 +1374,6 @@ retry:
		* The task is still there. We don't try
		* again, some other cpu will pull it when ready.
		*/
		dequeue_pushable_dl_task(rq, next_task);
		goto out;
		}

		@@ -1389,6 +1389,7 @@ retry:
		deactivate_task(rq, next_task, 0);
		set_task_cpu(next_task, later_rq->cpu);
		activate_task(later_rq, next_task, 0);
		ret = 1;

		resched_curr(later_rq);

		@@ -1397,7 +1398,7 @@ retry:
		out:
		put_task_struct(next_task);

		return 1;
		return ret;
		}

		static void push_dl_tasks(struct rq *rq)

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