[tip:sched/core] sched/numa: Consider 'imbalance_pct' when comparing loads in numa_has_capacity()

From: tip-bot for Srikar Dronamraju
Date: Tue Jul 07 2015 - 02:50:09 EST


Commit-ID: 44dcb04f0ea8eaac3b9c9d3172416efc5a950214
Gitweb: http://git.kernel.org/tip/44dcb04f0ea8eaac3b9c9d3172416efc5a950214
Author: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
AuthorDate: Tue, 16 Jun 2015 17:26:00 +0530
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 7 Jul 2015 08:46:10 +0200

sched/numa: Consider 'imbalance_pct' when comparing loads in numa_has_capacity()

This is consistent with all other load balancing instances where we
absorb unfairness upto env->imbalance_pct. Absorbing unfairness upto
env->imbalance_pct allows to pull and retain task to their preferred
nodes.

Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1434455762-30857-3-git-send-email-srikar@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 43ee84f..a53a610 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1415,8 +1415,9 @@ static bool numa_has_capacity(struct task_numa_env *env)
* --------------------- vs ---------------------
* src->compute_capacity dst->compute_capacity
*/
- if (src->load * dst->compute_capacity >
- dst->load * src->compute_capacity)
+ if (src->load * dst->compute_capacity * env->imbalance_pct >
+
+ dst->load * src->compute_capacity * 100)
return true;

return false;
--
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