This is a note to let you know that I've just added the patch titled block: only mark bio as tracked if it really is tracked to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-only-mark-bio-as-tracked-if-it-really-is-track.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6a52efe5286829a926e77cfcfa00024fadfe5d1e Author: Jens Axboe <axboe@xxxxxxxxx> Date: Fri Oct 15 20:06:18 2021 -0600 block: only mark bio as tracked if it really is tracked [ Upstream commit 90b8faa0e8de1b02b619fb33f6c6e1e13e7d1d70 ] We set BIO_TRACKED unconditionally when rq_qos_throttle() is called, even though we may not even have an rq_qos handler. Only mark it as TRACKED if it really is potentially tracked. This saves considerable time for the case where the bio isn't tracked: 2.64% -1.65% [kernel.vmlinux] [k] bio_endio Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h index f000f83e0621..3cfbc8668cba 100644 --- a/block/blk-rq-qos.h +++ b/block/blk-rq-qos.h @@ -189,9 +189,10 @@ static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) * BIO_TRACKED lets controllers know that a bio went through the * normal rq_qos path. */ - bio_set_flag(bio, BIO_TRACKED); - if (q->rq_qos) + if (q->rq_qos) { + bio_set_flag(bio, BIO_TRACKED); __rq_qos_throttle(q->rq_qos, bio); + } } static inline void rq_qos_track(struct request_queue *q, struct request *rq,