[PATCH 5.17 423/772] bfq: Allow current waker to defend against a tentative one

[Greg Kroah-Hartman]

From: Jan Kara <jack@xxxxxxx>

[ Upstream commit c5ac56bb6110e42e79d3106866658376b2e48ab9 ]

The code in bfq_check_waker() ignores wake up events from the current
waker. This makes it more likely we select a new tentative waker
although the current one is generating more wake up events. Treat
current waker the same way as any other process and allow it to reset
the waker detection logic.

Fixes: 71217df39dc6 ("block, bfq: make waker-queue detection more robust")
Signed-off-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20220519105235.31397-2-jack@xxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 block/bfq-iosched.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 047368c23984..31f430d9023d 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2133,8 +2133,7 @@ static void bfq_check_waker(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 	if (!bfqd->last_completed_rq_bfqq ||
 	    bfqd->last_completed_rq_bfqq == bfqq ||
 	    bfq_bfqq_has_short_ttime(bfqq) ||
-	    now_ns - bfqd->last_completion >= 4 * NSEC_PER_MSEC ||
-	    bfqd->last_completed_rq_bfqq == bfqq->waker_bfqq)
+	    now_ns - bfqd->last_completion >= 4 * NSEC_PER_MSEC)
 		return;
 
 	/*
-- 
2.35.1