From da521626ac620d8719d674a48b8ec3620eefd42a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 11 Aug 2021 09:20:04 -0600 Subject: [PATCH] bio: optimize initialization of a bio 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. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/bio.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/block/bio.c b/block/bio.c index 1fab762..6fa5c65 100644 --- a/block/bio.c +++ b/block/bio.c @@ -246,12 +246,40 @@ 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); - bio->bi_io_vec = table; bio->bi_max_vecs = max_vecs; + bio->bi_io_vec = table; + bio->bi_pool = NULL; } EXPORT_SYMBOL(bio_init); -- 2.7.4