From bb3bac2ca9a3a5b7fa601781adf70167a0449d75 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Mon, 6 Feb 2017 11:04:26 -0500 Subject: [PATCH] sched/core: Remove unlikely() annotation from sched_move_task() The check for 'running' in sched_move_task() has an unlikely() around it. That is, it is unlikely that the task being moved is running. That use to be true. But with a couple of recent updates, it is now likely that the task will be running. The first change came from ea86cb4b7621 ("sched/cgroup: Fix cpu_cgroup_fork() handling") that moved around the use case of sched_move_task() in do_fork() where the call is now done after the task is woken (hence it is running). The second change came from 8e5bfa8c1f84 ("sched/autogroup: Do not use autogroup->tg in zombie threads") where sched_move_task() is called by the exit path, by the task that is exiting. Hence it too is running. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vincent Guittot Link: http://lkml.kernel.org/r/20170206110426.27ca6426@gandalf.local.home Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e4aa470ed454..34e2291a9a6c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6404,14 +6404,14 @@ void sched_move_task(struct task_struct *tsk) if (queued) dequeue_task(rq, tsk, DEQUEUE_SAVE | DEQUEUE_MOVE); - if (unlikely(running)) + if (running) put_prev_task(rq, tsk); sched_change_group(tsk, TASK_MOVE_GROUP); if (queued) enqueue_task(rq, tsk, ENQUEUE_RESTORE | ENQUEUE_MOVE); - if (unlikely(running)) + if (running) set_curr_task(rq, tsk); task_rq_unlock(rq, tsk, &rf);