blk-wbt: use wq_has_sleeper() for wq active check
authorJens Axboe <axboe@kernel.dk>
Mon, 20 Aug 2018 19:20:50 +0000 (13:20 -0600)
committerJens Axboe <axboe@kernel.dk>
Wed, 22 Aug 2018 21:07:31 +0000 (15:07 -0600)
We need the memory barrier before checking the list head,
use the appropriate helper for this. The matching queue
side memory barrier is provided by set_current_state().

Tested-by: Anchal Agarwal <anchalag@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/blk-wbt.c

index 1dd7edc..853e224 100644 (file)
@@ -118,7 +118,7 @@ static void rwb_wake_all(struct rq_wb *rwb)
        for (i = 0; i < WBT_NUM_RWQ; i++) {
                struct rq_wait *rqw = &rwb->rq_wait[i];
 
-               if (waitqueue_active(&rqw->wait))
+               if (wq_has_sleeper(&rqw->wait))
                        wake_up_all(&rqw->wait);
        }
 }
@@ -162,7 +162,7 @@ static void __wbt_done(struct rq_qos *rqos, enum wbt_flags wb_acct)
        if (inflight && inflight >= limit)
                return;
 
-       if (waitqueue_active(&rqw->wait)) {
+       if (wq_has_sleeper(&rqw->wait)) {
                int diff = limit - inflight;
 
                if (!inflight || diff >= rwb->wb_background / 2)
@@ -493,8 +493,8 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
        struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);
        DECLARE_WAITQUEUE(wait, current);
 
-       if (!waitqueue_active(&rqw->wait)
-               && rq_wait_inc_below(rqw, get_limit(rwb, rw)))
+       if (!wq_has_sleeper(&rqw->wait) &&
+           rq_wait_inc_below(rqw, get_limit(rwb, rw)))
                return;
 
        add_wait_queue_exclusive(&rqw->wait, &wait);