The memory barriers in list_del_init_careful() and list_empty_careful() in pairs already handle the proper ordering between data.got_token and data.wq.entry. So remove the redundant explicit barriers. And also change a "break" statement to "return" to avoid redundant calling of finish_wait(). Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> --- block/blk-rq-qos.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c index dc510f493ba57..9b0aa7dd6779f 100644 --- a/block/blk-rq-qos.c +++ b/block/blk-rq-qos.c @@ -218,7 +218,6 @@ static int rq_qos_wake_function(struct wait_queue_entry *curr, return -1; data->got_token = true; - smp_wmb(); wake_up_process(data->task); list_del_init_careful(&curr->entry); return 1; @@ -274,10 +273,9 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data, * which means we now have two. Put our local token * and wake anyone else potentially waiting for one. */ - smp_rmb(); if (data.got_token) cleanup_cb(rqw, private_data); - break; + return; } io_schedule(); has_sleeper = true; -- 2.20.1
