Commit 743cb1ff authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

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: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Acked-by: default avatarVincent 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.lanSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 98a96f20
...@@ -6248,7 +6248,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s ...@@ -6248,7 +6248,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
return fix_small_imbalance(env, sds); 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. * 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 * Except of course for the group_imb case, since then we might
......
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