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

[tip-bot for Srikar Dronamraju <tipbot@zytor.com>]

Commit-ID:  44dcb04f0ea8eaac3b9c9d3172416efc5a950214
Gitweb:     http://git.kernel.org/tip/44dcb04f0ea8eaac3b9c9d3172416efc5a950214
Author:     Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Tue, 16 Jun 2015 17:26:00 +0530
Committer:  Ingo Molnar <mingo@kernel.org>
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@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1434455762-30857-3-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 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;