Commit-ID: 804968809c321066cca028d4cbd533a420f964bc Gitweb: http://git.kernel.org/tip/804968809c321066cca028d4cbd533a420f964bc Author: Wanpeng Li <[email protected]> AuthorDate: Fri, 31 Oct 2014 06:39:32 +0800 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 4 Nov 2014 07:17:53 +0100
sched/deadline: Fix artificial overrun introduced by yield_task_dl() The yield semantic of deadline class is to reduce remaining runtime to zero, and then update_curr_dl() will stop it. However, comsumed bandwidth is reduced from the budget of yield task again even if it has already been set to zero which leads to artificial overrun. This patch fix it by make sure we don't steal some more time from the task that yielded in update_curr_dl(). Suggested-by: Juri Lelli <[email protected]> Signed-off-by: Wanpeng Li <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Kirill Tkhai <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/deadline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9d483e8..c047a94 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -628,7 +628,7 @@ static void update_curr_dl(struct rq *rq) sched_rt_avg_update(rq, delta_exec); - dl_se->runtime -= delta_exec; + dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec; if (dl_runtime_exceeded(rq, dl_se)) { __dequeue_task_dl(rq, curr, 0); if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted))) -- 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/
