sched: Add a lock break for PREEMPT=y

Since load-balancing can hold rq->locks for quite a long while, allow
breaking out early when there is lock contention.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-12-17 18:10:09 +01:00 committed by Ingo Molnar
parent 230059de77
commit baa8c1102f

View File

@ -2065,6 +2065,10 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
*/
if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
break;
if (raw_spin_is_contended(&this_rq->lock) ||
raw_spin_is_contended(&busiest->lock))
break;
#endif
} while (load_moved && max_load_move > total_load_moved);