sched/fair: Make calculate_imbalance() independent
authorPeter Zijlstra <peterz@infradead.org>
Tue, 29 Jul 2014 15:00:21 +0000 (17:00 +0200)
committerIngo Molnar <mingo@kernel.org>
Tue, 12 Aug 2014 10:48:18 +0000 (12:48 +0200)
commit743cb1ff191f00fee653212bdbcee1e56086d6ce
tree0a6213fa99f27404f07e2e38f29ce93ae9bbf588
parent98a96f202203fecad65b44449077c695686ad4db
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