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 Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> --- block/blk-rq-qos.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) 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, -- 2.33.1