From 28747fcd2211d0fccbe3d3c91a1067c3744db908 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Matias=20Bj=C3=B8rling?= Date: Wed, 11 Jun 2014 23:43:54 +0200 Subject: [PATCH] block: remove WQ_POWER_EFFICIENT from kblockd MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit blk-mq issues async requests through kblockd. To issue a work request on a specific CPU, kblockd_schedule_delayed_work_on is used. However, the specific CPU choice may not be honored, if the power_efficient option for workqueues is set. blk-mq requires that we have strict per-cpu scheduling, so it wont work properly if kblockd is marked POWER_EFFICIENT and power_efficient is set. Remove the kblockd WQ_POWER_EFFICIENT flag to prevent this behavior. This essentially reverts part of commit 695588f9454b, which added the WQ_POWER_EFFICIENT marker to kblockd. Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- block/blk-core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 9aca8c7..55f91b8 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -3311,8 +3311,7 @@ int __init blk_dev_init(void) /* used for unplugging and affects IO latency/throughput - HIGHPRI */ kblockd_workqueue = alloc_workqueue("kblockd", - WQ_MEM_RECLAIM | WQ_HIGHPRI | - WQ_POWER_EFFICIENT, 0); + WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); if (!kblockd_workqueue) panic("Failed to create kblockd\n"); -- 2.7.4