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| author | Ingo Molnar <mingo@kernel.org> | 2016-05-11 08:25:53 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-05-11 08:25:53 +0200 |
| commit | 53d3bc773eaa7ab1cf63585e76af7ee869d5e709 (patch) | |
| tree | db53cf2c46e8a052f624889ff8283d0495280b85 /kernel | |
| parent | c5114626f33b62fa7595e57d87f33d9d1f8298a2 (diff) | |
| download | blackbird-op-linux-53d3bc773eaa7ab1cf63585e76af7ee869d5e709.tar.gz blackbird-op-linux-53d3bc773eaa7ab1cf63585e76af7ee869d5e709.zip | |
Revert "sched/fair: Fix fairness issue on migration"
Mike reported that this recent commit:
3a47d5124a95 ("sched/fair: Fix fairness issue on migration")
... broke interactivity and the signal starvation test.
We have a proper fix series in the works but ran out of time for
v4.6, so revert the commit.
Reported-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 40748dc8ea3e..e7dd0ec169be 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3188,25 +3188,17 @@ static inline void check_schedstat_required(void) static void enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { - bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING); - bool curr = cfs_rq->curr == se; - /* - * If we're the current task, we must renormalise before calling - * update_curr(). + * Update the normalized vruntime before updating min_vruntime + * through calling update_curr(). */ - if (renorm && curr) + if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING)) se->vruntime += cfs_rq->min_vruntime; - update_curr(cfs_rq); - /* - * Otherwise, renormalise after, such that we're placed at the current - * moment in time, instead of some random moment in the past. + * Update run-time statistics of the 'current'. */ - if (renorm && !curr) - se->vruntime += cfs_rq->min_vruntime; - + update_curr(cfs_rq); enqueue_entity_load_avg(cfs_rq, se); account_entity_enqueue(cfs_rq, se); update_cfs_shares(cfs_rq); @@ -3222,7 +3214,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) update_stats_enqueue(cfs_rq, se); check_spread(cfs_rq, se); } - if (!curr) + if (se != cfs_rq->curr) __enqueue_entity(cfs_rq, se); se->on_rq = 1; |
