Messages in this thread Patch in this message | | | Date | Tue, 12 Aug 2014 07:52:10 -0700 | From | tip-bot for Peter Zijlstra <> | Subject | [tip:sched/core] sched/fair: Make calculate_imbalance() independent |
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Commit-ID: 743cb1ff191f00fee653212bdbcee1e56086d6ce Gitweb: http://git.kernel.org/tip/743cb1ff191f00fee653212bdbcee1e56086d6ce Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Tue, 29 Jul 2014 17:00:21 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 12 Aug 2014 12:48:18 +0200
sched/fair: Make calculate_imbalance() independent
Rik noticed that calculate_imbalance() relies on update_sd_pick_busiest() to guarantee that busiest->sum_nr_running > busiest->group_capacity_factor.
Break this implicit assumption (with the intent of not providing it anymore) by having calculat_imbalance() verify it and not rely on others.
Reported-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140729152631.GW12054@laptop.lan Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index bfa3c86..e9477e6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6248,7 +6248,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s return fix_small_imbalance(env, sds); } - if (!busiest->group_imb) { + if (busiest->sum_nr_running > busiest->group_capacity_factor) { /* * Don't want to pull so many tasks that a group would go idle. * Except of course for the group_imb case, since then we might
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