Commit-ID: fc79e240be5aa379dd36a62158be5a5ee0e4aec7 Gitweb: http://git.kernel.org/tip/fc79e240be5aa379dd36a62158be5a5ee0e4aec7 Author: Kirill Tkhai <tkhai@xxxxxxxxx> AuthorDate: Wed, 30 Jan 2013 16:50:36 +0400 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 31 Jan 2013 10:31:13 +0100 sched/rt: Do not account zero delta_exec in update_curr_rt() There are several places of consecutive calls of dequeue_task_rt() and put_prev_task_rt() in the scheduler. For example, function rt_mutex_setprio() does it. The both calls lead to update_curr_rt(), the second of it receives zeroed delta_exec. The only effective action in this case is call of sched_rt_avg_update(), which can change rq->age_stamp and rq->rt_avg. But it is possible in case of ""floating"" rq->clock. This fact is not reasonable to be accounted. Another actions do nothing. Signed-off-by: Kirill V Tkhai <tkhai@xxxxxxxxx> Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CC: linux-rt-users <linux-rt-users@xxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/931541359550236@xxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/sched/rt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 2f69ca9..94abca4 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -925,8 +925,8 @@ static void update_curr_rt(struct rq *rq) return; delta_exec = rq->clock_task - curr->se.exec_start; - if (unlikely((s64)delta_exec < 0)) - delta_exec = 0; + if (unlikely((s64)delta_exec <= 0)) + return; schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
