sched: sync wakeups preempt too

make sure sync wakeups preempt too - the scheduler will not
overschedule as we've got various throttles against that.
As a result, sync wakeups can be used more widely in the kernel
(to signal wakeup affinity between tasks), and no arbitrary
latencies will be introduced either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 10 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 7fd343462597..bba57adb9504 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1596,16 +1596,7 @@ out_activate:
                 schedstat_inc(p, se.nr_wakeups_remote);
         update_rq_clock(rq);
         activate_task(rq, p, 1);
-        /*
-         * Sync wakeups (i.e. those types of wakeups where the waker
-         * has indicated that it will leave the CPU in short order)
-         * don't trigger a preemption, if the woken up task will run on
-         * this cpu. (in this case the 'I will reschedule' promise of
-         * the waker guarantees that the freshly woken up task is going
-         * to be considered on this CPU.)
-         */
-        if (!sync || rq->curr == rq->idle)
-                check_preempt_curr(rq, p);
+        check_preempt_curr(rq, p);
         success = 1;
 
 out_running: