block: streamline bvec_alloc
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>
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f2c3eb9bb0
commit
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26
block/bio.c
26
block/bio.c
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@ -172,8 +172,6 @@ static inline gfp_t bvec_alloc_gfp(gfp_t gfp)
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struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
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mempool_t *pool)
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{
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struct bio_vec *bvl;
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/*
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* see comment near bvec_array define!
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*/
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@ -201,28 +199,24 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
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}
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/*
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* idx now points to the pool we want to allocate from. only the
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* 1-vec entry pool is mempool backed.
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* Try a slab allocation first for all smaller allocations. If that
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* fails and __GFP_DIRECT_RECLAIM is set retry with the mempool.
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* The mempool is sized to handle up to BIO_MAX_PAGES entries.
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*/
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if (*idx == BVEC_POOL_MAX) {
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fallback:
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bvl = mempool_alloc(pool, gfp_mask);
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} else {
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if (*idx < BVEC_POOL_MAX) {
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struct biovec_slab *bvs = bvec_slabs + *idx;
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struct bio_vec *bvl;
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/*
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* Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM
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* is set, retry with the 1-entry mempool
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*/
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bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask));
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if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) {
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*idx = BVEC_POOL_MAX;
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goto fallback;
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if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) {
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(*idx)++;
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return bvl;
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}
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*idx = BVEC_POOL_MAX;
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}
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(*idx)++;
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return bvl;
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return mempool_alloc(pool, gfp_mask);
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}
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void bio_uninit(struct bio *bio)
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