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| author | Jens Axboe <axboe@kernel.dk> | 2021-10-13 12:43:41 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-18 06:17:36 -0600 |
| commit | abd45c159df5fcb7ac820e2825dac85de7c01c21 (patch) | |
| tree | 8ab589415f5cc81205263a0813109deee6ffc067 /block/blk-merge.c | |
| parent | 09ce8744253a038eb658c14f9dc3b77fa021fc9f (diff) | |
| download | linux-abd45c159df5fcb7ac820e2825dac85de7c01c21.tar.gz | |
block: handle fast path of bio splitting inline
The fast path is no splitting needed. Separate the handling into a check part we can inline, and an out-of-line handling path if we do need to split. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index f88d7863f997..ec727234ac48 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -324,6 +324,7 @@ split: /** * __blk_queue_split - split a bio and submit the second half + * @q: [in] request_queue new bio is being queued at * @bio: [in, out] bio to be split * @nr_segs: [out] number of segments in the first bio * @@ -334,9 +335,9 @@ split: * of the caller to ensure that q->bio_split is only released after processing * of the split bio has finished. */ -void __blk_queue_split(struct bio **bio, unsigned int *nr_segs) +void __blk_queue_split(struct request_queue *q, struct bio **bio, + unsigned int *nr_segs) { - struct request_queue *q = (*bio)->bi_bdev->bd_disk->queue; struct bio *split = NULL; switch (bio_op(*bio)) { @@ -353,21 +354,6 @@ void __blk_queue_split(struct bio **bio, unsigned int *nr_segs) nr_segs); break; default: - /* - * All drivers must accept single-segments bios that are <= - * PAGE_SIZE. This is a quick and dirty check that relies on - * the fact that bi_io_vec[0] is always valid if a bio has data. - * The check might lead to occasional false negatives when bios - * are cloned, but compared to the performance impact of cloned - * bios themselves the loop below doesn't matter anyway. - */ - if (!q->limits.chunk_sectors && - (*bio)->bi_vcnt == 1 && - ((*bio)->bi_io_vec[0].bv_len + - (*bio)->bi_io_vec[0].bv_offset) <= PAGE_SIZE) { - *nr_segs = 1; - break; - } split = blk_bio_segment_split(q, *bio, &q->bio_split, nr_segs); break; } @@ -397,9 +383,11 @@ void __blk_queue_split(struct bio **bio, unsigned int *nr_segs) */ void blk_queue_split(struct bio **bio) { + struct request_queue *q = (*bio)->bi_bdev->bd_disk->queue; unsigned int nr_segs; - __blk_queue_split(bio, &nr_segs); + if (blk_may_split(q, *bio)) + __blk_queue_split(q, bio, &nr_segs); } EXPORT_SYMBOL(blk_queue_split); |