Avoid the pointless goto by trying the slab allocation first and falling
through to the mempool.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/bio.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index c2152c4bf8a317..321b3479a154da 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -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)
--
2.29.2
