The patch aims to decrease the number of calls of push_rt_task() in push_rt_tasks().
It's not necessary to push more than 'num_online_cpus() - 1' tasks. If just pushed task doesn't leave its new CPU during our local call of push_rt_tasks() than we won't push another task to the CPU. If it leave or change priority than it will pull new task by itself. Signed-off-by: Kirill V Tkhai <[email protected]> CC: Steven Rostedt <[email protected]> CC: Ingo Molnar <[email protected]> CC: Peter Zijlstra <[email protected]> CC: linux-rt-users <[email protected]> --- kernel/sched/rt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 4e8f0f4..edf046d 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1703,8 +1703,10 @@ out: static void push_rt_tasks(struct rq *rq) { + int num_cpus = num_online_cpus() - 1; + /* push_rt_task will return true if it moved an RT */ - while (push_rt_task(rq)) + while (push_rt_task(rq) && --num_cpus > 0) ; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
