From 478eb72b815f33734723867ff236d96afa418d69 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 19 Oct 2021 22:24:12 +0100 Subject: [PATCH] block: optimise req_bio_endio() First, get rid of an extra branch and chain error checks. Also reshuffle it with bio_advance(), so it goes closer to the final check, with that the compiler loads rq->rq_flags only once, and also doesn't reload bio->bi_iter.bi_size if bio_advance() didn't actually advanced the iter. Reviewed-by: Christoph Hellwig Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- block/blk-mq.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 31d9e61..8b05a8f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -633,25 +633,23 @@ void blk_mq_free_plug_rqs(struct blk_plug *plug) static void req_bio_endio(struct request *rq, struct bio *bio, unsigned int nbytes, blk_status_t error) { - if (error) + if (unlikely(error)) { bio->bi_status = error; - - if (unlikely(rq->rq_flags & RQF_QUIET)) - bio_set_flag(bio, BIO_QUIET); - - bio_advance(bio, nbytes); - - if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) { + } else if (req_op(rq) == REQ_OP_ZONE_APPEND) { /* * Partial zone append completions cannot be supported as the * BIO fragments may end up not being written sequentially. */ - if (bio->bi_iter.bi_size) + if (bio->bi_iter.bi_size == nbytes) bio->bi_status = BLK_STS_IOERR; else bio->bi_iter.bi_sector = rq->__sector; } + bio_advance(bio, nbytes); + + if (unlikely(rq->rq_flags & RQF_QUIET)) + bio_set_flag(bio, BIO_QUIET); /* don't actually finish bio if it's part of flush sequence */ if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ)) bio_endio(bio); -- 2.7.4