4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Xunlei Pang <[email protected]> commit ae83b56a56f8d9643dedbee86b457fa1c5d42f59 upstream. 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 <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Daniel Bristot de Oliveira <[email protected]> Cc: Juri Lelli <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luca Abeni <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: df8eac8cafce ("sched/deadline: Throttle a constrained deadline task activated after the deadline) Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Cc: Ben Hutchings <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/sched/deadline.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -732,6 +732,8 @@ static inline void dl_check_constrained_ 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; } }
