[PATCH 2/2] sched: load_balance: Reset env when going to redo due to all pinned

From: Vladimir Davydov
Date: Sun Sep 15 2013 - 13:30:43 EST


Firstly, reset env.dst_cpu/dst_rq to this_cpu/this_rq, because it could
have changed in 'some pinned' case. Otherwise, should_we_balance() can
stop balancing beforehand.

Secondly, reset env.flags, because it can have LBF_SOME_PINNED set.

Thirdly, reset env.dst_grpmask cpus in env.cpus to allow handling 'some
pinned' case when pulling tasks from a new busiest cpu.

Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
kernel/sched/fair.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cd59640..d840e51 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5289,8 +5289,16 @@ more_balance:
if (unlikely(env.flags & LBF_ALL_PINNED)) {
cpumask_clear_cpu(cpu_of(busiest), cpus);
if (!cpumask_empty(cpus)) {
- env.loop = 0;
- env.loop_break = sched_nr_migrate_break;
+ env.dst_cpu = this_cpu;
+ env.dst_rq = this_rq;
+ env.flags = 0;
+ env.loop = 0;
+ env.loop_break = sched_nr_migrate_break;
+
+ /* Reset cpus cleared in LBF_SOME_PINNED case */
+ if (env.dst_grpmask)
+ cpumask_or(cpus, cpus, env.dst_grpmask);
+
goto redo;
}
goto out_balanced;
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/