From ae83b56a56f8d9643dedbee86b457fa1c5d42f59 Mon Sep 17 00:00:00 2001
From: Xunlei Pang <xlpang@redhat.com>
Date: Wed, 10 May 2017 21:03:37 +0800
Subject: [PATCH] sched/deadline: Zero out positive runtime after throttling constrained tasks
Git-commit: ae83b56a56f8d9643dedbee86b457fa1c5d42f59
Patch-mainline: v4.13-rc1
References: bsc#978907
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 <xlpang@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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 <mingo@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
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;
}
}
--
2.12.0