From ae83b56a56f8d9643dedbee86b457fa1c5d42f59 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Wed, 10 May 2017 21:03:37 +0800 Subject: [PATCH] sched/deadline: Zero out positive runtime after throttling constrained tasks When a contrained task is throttled by dl_check_constrained_dl(), it may carry the remaining positive runtime, as a result when dl_task_timer() fires and calls replenish_dl_entity(), it will not be replenished correctly due to the positive dl_se->runtime. This patch assigns its runtime to 0 if positive after throttling. Signed-off-by: Xunlei Pang Signed-off-by: Peter Zijlstra (Intel) Acked-by: Daniel Bristot de Oliveira Cc: Juri Lelli Cc: Linus Torvalds Cc: Luca Abeni Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Fixes: df8eac8cafce ("sched/deadline: Throttle a constrained deadline task activated after the deadline) Link: http://lkml.kernel.org/r/1494421417-27550-1-git-send-email-xlpang@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e3b25dfb74f3..54302cf68bb9 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -941,6 +941,8 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se) if (unlikely(dl_se->dl_boosted || !start_dl_timer(p))) return; dl_se->dl_throttled = 1; + if (dl_se->runtime > 0) + dl_se->runtime = 0; } }