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authorChristoph Hellwig <hch@lst.de>2022-07-27 19:22:56 +0300
committerJens Axboe <axboe@kernel.dk>2022-08-03 02:22:54 +0300
commit51d798cdb5c219000fe76a3ffbcaa846b689ba80 (patch)
treef80c9ae63c33edb1fbb31c1e92d4c46253aea4c4 /block
parent5a97806f7dc069d9561d9930a2ae108700e222ab (diff)
downloadlinux-51d798cdb5c219000fe76a3ffbcaa846b689ba80.tar.xz
block: change the blk_queue_bounce calling convention
The double indirect bio leads to somewhat suboptimal code generation. Instead return the (original or split) bio, and make sure the request_queue arguments to the lower level helpers is passed after the bio to avoid constant reshuffling of the argument passing registers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq.c2
-rw-r--r--block/blk.h10
-rw-r--r--block/bounce.c26
3 files changed, 20 insertions, 18 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 790f55453f1b..7adba3eeba1c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2815,7 +2815,7 @@ void blk_mq_submit_bio(struct bio *bio)
unsigned int nr_segs = 1;
blk_status_t ret;
- blk_queue_bounce(q, &bio);
+ bio = blk_queue_bounce(bio, q);
if (bio_may_exceed_limits(bio, q))
bio = __bio_split_to_limits(bio, q, &nr_segs);
diff --git a/block/blk.h b/block/blk.h
index 623be4c2e60c..f50c8fcded99 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -378,7 +378,7 @@ static inline void blk_throtl_bio_endio(struct bio *bio) { }
static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
#endif
-void __blk_queue_bounce(struct request_queue *q, struct bio **bio);
+struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
static inline bool blk_queue_may_bounce(struct request_queue *q)
{
@@ -387,10 +387,12 @@ static inline bool blk_queue_may_bounce(struct request_queue *q)
max_low_pfn >= max_pfn;
}
-static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
+static inline struct bio *blk_queue_bounce(struct bio *bio,
+ struct request_queue *q)
{
- if (unlikely(blk_queue_may_bounce(q) && bio_has_data(*bio)))
- __blk_queue_bounce(q, bio);
+ if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
+ return __blk_queue_bounce(bio, q);
+ return bio;
}
#ifdef CONFIG_BLK_CGROUP_IOLATENCY
diff --git a/block/bounce.c b/block/bounce.c
index c8f487af7be3..7cfcb242f9a1 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -199,24 +199,24 @@ err_put:
return NULL;
}
-void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
+struct bio *__blk_queue_bounce(struct bio *bio_orig, struct request_queue *q)
{
struct bio *bio;
- int rw = bio_data_dir(*bio_orig);
+ int rw = bio_data_dir(bio_orig);
struct bio_vec *to, from;
struct bvec_iter iter;
unsigned i = 0, bytes = 0;
bool bounce = false;
int sectors;
- bio_for_each_segment(from, *bio_orig, iter) {
+ bio_for_each_segment(from, bio_orig, iter) {
if (i++ < BIO_MAX_VECS)
bytes += from.bv_len;
if (PageHighMem(from.bv_page))
bounce = true;
}
if (!bounce)
- return;
+ return bio_orig;
/*
* Individual bvecs might not be logical block aligned. Round down
@@ -225,13 +225,13 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
*/
sectors = ALIGN_DOWN(bytes, queue_logical_block_size(q)) >>
SECTOR_SHIFT;
- if (sectors < bio_sectors(*bio_orig)) {
- bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
- bio_chain(bio, *bio_orig);
- submit_bio_noacct(*bio_orig);
- *bio_orig = bio;
+ if (sectors < bio_sectors(bio_orig)) {
+ bio = bio_split(bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
+ bio_chain(bio, bio_orig);
+ submit_bio_noacct(bio_orig);
+ bio_orig = bio;
}
- bio = bounce_clone_bio(*bio_orig);
+ bio = bounce_clone_bio(bio_orig);
/*
* Bvec table can't be updated by bio_for_each_segment_all(),
@@ -254,7 +254,7 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
to->bv_page = bounce_page;
}
- trace_block_bio_bounce(*bio_orig);
+ trace_block_bio_bounce(bio_orig);
bio->bi_flags |= (1 << BIO_BOUNCED);
@@ -263,6 +263,6 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
else
bio->bi_end_io = bounce_end_io_write;
- bio->bi_private = *bio_orig;
- *bio_orig = bio;
+ bio->bi_private = bio_orig;
+ return bio;
}