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block: streamline bvec_alloc

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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>
This commit is contained in:
Christoph Hellwig 2021-02-02 18:19:22 +01:00 committed by Jens Axboe
parent f2c3eb9bb0
commit f007a3d66c
1 changed files with 10 additions and 16 deletions
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26
block/bio.c
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@ -172,8 +172,6 @@ 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!
*/
@ -201,28 +199,24 @@ 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)