Commit-ID: 193be41e33168a3a06eb9d356d9e39c69de161d2 Gitweb: http://git.kernel.org/tip/193be41e33168a3a06eb9d356d9e39c69de161d2 Author: Joel Fernandes <joe...@google.com> AuthorDate: Wed, 12 Jul 2017 19:24:29 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 14 Jul 2017 10:35:16 +0200
sched/deadline: Fix confusing comments about selection of top pi-waiter This comment in the code is incomplete, and I believe it begs a definition of dl_boosted to make sense of the condition that follows. Rewrite the comment and also rearrange the condition that follows to reflect the first condition "we have a top pi-waiter which is a SCHED_DEADLINE task" in that order. Also fix a typo that follows. Signed-off-by: Joel Fernandes <joe...@google.com> Reviewed-by: Daniel Bristot de Oliveira <bris...@redhat.com> Acked-by: Juri Lelli <juri.le...@arm.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/20170713022429.10307-1-joe...@google.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/deadline.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index a84299f..755bd3f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1392,17 +1392,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) struct sched_dl_entity *pi_se = &p->dl; /* - * Use the scheduling parameters of the top pi-waiter - * task if we have one and its (absolute) deadline is - * smaller than our one... OTW we keep our runtime and - * deadline. + * Use the scheduling parameters of the top pi-waiter task if: + * - we have a top pi-waiter which is a SCHED_DEADLINE task AND + * - our dl_boosted is set (i.e. the pi-waiter's (absolute) deadline is + * smaller than our deadline OR we are a !SCHED_DEADLINE task getting + * boosted due to a SCHED_DEADLINE pi-waiter). + * Otherwise we keep our runtime and deadline. */ - if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) { + if (pi_task && dl_prio(pi_task->normal_prio) && p->dl.dl_boosted) { 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 + * that is going to be deboosted, but exceeds its * runtime while doing so. No point in replenishing * it, as it's going to return back to its original * scheduling class after this.
