Commit-ID: 64be6f1f5f710f5995d41caf8a1767fe6d2b5a87 Gitweb: http://git.kernel.org/tip/64be6f1f5f710f5995d41caf8a1767fe6d2b5a87 Author: Juri Lelli <[email protected]> AuthorDate: Fri, 24 Oct 2014 10:16:37 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 28 Oct 2014 10:46:00 +0100
sched/deadline: Don't replenish from a !SCHED_DEADLINE entity In the deboost path, right after the dl_boosted flag has been reset, we can currently end up replenishing using -deadline parameters of a !SCHED_DEADLINE entity. This of course causes a bug, as those parameters are empty. In the case depicted above it is safe to simply bail out, as the deboosted task is going to be back to its original scheduling class anyway. Reported-by: Daniel Wagner <[email protected]> Tested-by: Daniel Wagner <[email protected]> Signed-off-by: Juri Lelli <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Cc: Dario Faggioli <[email protected]> Cc: Michael Trimarchi <[email protected]> Cc: Fabio Checconi <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/deadline.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 256e577..92279ea 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -847,8 +847,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) * smaller than our one... OTW we keep our runtime and * deadline. */ - if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) + if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) { pi_se = &pi_task->dl; + } else if (!dl_prio(p->normal_prio)) { + /* + * Special case in which we have a !SCHED_DEADLINE task + * that is going to be deboosted, but exceedes its + * runtime while doing so. No point in replenishing + * it, as it's going to return back to its original + * scheduling class after this. + */ + BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH); + return; + } /* * If p is throttled, we do nothing. In fact, if it exhausted -- 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/
