[PATCH 1/6] bio: optimize initialization of a bio
From: Jens Axboe <axboe@kernel.dk>
Date: 2021-08-12 15:41:54
Also in:
linux-block
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
The memset() used is measurably slower in targeted benchmarks, wasting about 1% of the total runtime, or 50% of the (later) hot path cached bio alloc. Get rid of it and fill in the bio manually. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/bio.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index 1fab762e079b..9bf98b877aba 100644
--- a/block/bio.c
+++ b/block/bio.c@@ -246,7 +246,34 @@ static void bio_free(struct bio *bio) void bio_init(struct bio *bio, struct bio_vec *table, unsigned short max_vecs) { - memset(bio, 0, sizeof(*bio)); + bio->bi_next = NULL; + bio->bi_bdev = NULL; + bio->bi_opf = 0; + bio->bi_flags = 0; + bio->bi_ioprio = 0; + bio->bi_write_hint = 0; + bio->bi_status = 0; + bio->bi_iter.bi_sector = 0; + bio->bi_iter.bi_size = 0; + bio->bi_iter.bi_idx = 0; + bio->bi_iter.bi_bvec_done = 0; + bio->bi_end_io = NULL; + bio->bi_private = NULL; +#ifdef CONFIG_BLK_CGROUP + bio->bi_blkg = NULL; + bio->bi_issue.value = 0; +#ifdef CONFIG_BLK_CGROUP_IOCOST + bio->bi_iocost_cost = 0; +#endif +#endif +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + bio->bi_crypt_context = NULL; +#endif +#ifdef CONFIG_BLK_DEV_INTEGRITY + bio->bi_integrity = NULL; +#endif + bio->bi_vcnt = 0; + atomic_set(&bio->__bi_remaining, 1); atomic_set(&bio->__bi_cnt, 1);
--
2.32.0