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,
