[PATCH] sched: Fix task_tick_fair from disabling numa_balancing

[PATCH] sched: Fix task_tick_fair from disabling numa_balancing

[Srikar Dronamraju]

If static branch sched_numa_balancing is enabled, it should kickstart
numa_balancing through task_tick_numa(). However Commit 2a1ed24
("sched/numa: Convert sched_numa_balancing to a static_branch")
erroneously disables this.

Fix this anomaly by enabling task_tick_numa when static branch
sched_numa_balancing is enabled.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 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 4df37a4..3bdc3da 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7881,7 +7881,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 		entity_tick(cfs_rq, se, queued);
 	}
 
-	if (!static_branch_unlikely(&sched_numa_balancing))
+	if (static_branch_unlikely(&sched_numa_balancing))
 		task_tick_numa(rq, curr);
 }
 
-- 
2.1.4

[tip:sched/core] sched/numa: Fix task_tick_fair() from disabling numa_balancing

[tip-bot for Srikar Dronamraju]

Commit-ID:  b52da86e0ad58f096710977fcda856fd84da9233
Gitweb:     http://git.kernel.org/tip/b52da86e0ad58f096710977fcda856fd84da9233
Author:     Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 2 Oct 2015 07:48:25 +0530
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 6 Oct 2015 17:08:21 +0200

sched/numa: Fix task_tick_fair() from disabling numa_balancing

If static branch 'sched_numa_balancing' is enabled, it should kickstart
NUMA balancing through task_tick_numa(). However the following commit:

  2a595721a1fa ("sched/numa: Convert sched_numa_balancing to a static_branch")

erroneously disables this.

Fix this anomaly by enabling task_tick_numa() when the static branch
'sched_numa_balancing' is enabled.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443752305-27413-1-git-send-email-srikar@linux.vnet.ibm.com
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 4df37a4..3bdc3da 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7881,7 +7881,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 		entity_tick(cfs_rq, se, queued);
 	}
 
-	if (!static_branch_unlikely(&sched_numa_balancing))
+	if (static_branch_unlikely(&sched_numa_balancing))
 		task_tick_numa(rq, curr);
 }