From: Christoph Hellwig <hch@lst.de> mainline inclusion from mainline-v5.12-rc1 commit f007a3d66c5480c8dae3fa20a89a06861ef1f5db bugzilla: https://gitee.com/openeuler/kernel/issues/IB7FJU Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Avoid the pointless goto by trying the slab allocation first and falling through to the mempool. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Signed-off-by: Li Nan <linan122@huawei.com> --- block/bio.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/block/bio.c b/block/bio.c index 78c567bff06e..c20c02f43535 100644 --- a/block/bio.c +++ b/block/bio.c @@ -181,8 +181,6 @@ static inline gfp_t bvec_alloc_gfp(gfp_t gfp) struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, mempool_t *pool) { - struct bio_vec *bvl; - /* * see comment near bvec_array define! */ @@ -210,28 +208,24 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, } /* - * idx now points to the pool we want to allocate from. only the - * 1-vec entry pool is mempool backed. + * Try a slab allocation first for all smaller allocations. If that + * fails and __GFP_DIRECT_RECLAIM is set retry with the mempool. + * The mempool is sized to handle up to BIO_MAX_PAGES entries. */ - if (*idx == BVEC_POOL_MAX) { -fallback: - bvl = mempool_alloc(pool, gfp_mask); - } else { + if (*idx < BVEC_POOL_MAX) { struct biovec_slab *bvs = bvec_slabs + *idx; + struct bio_vec *bvl; - /* - * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM - * is set, retry with the 1-entry mempool - */ bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask)); - if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) { - *idx = BVEC_POOL_MAX; - goto fallback; + if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) { + (*idx)++; + return bvl; } + *idx = BVEC_POOL_MAX; } (*idx)++; - return bvl; + return mempool_alloc(pool, gfp_mask); } void bio_uninit(struct bio *bio) -- 2.39.2