From 9f180e315a93cde559ac1c9c4c5ce980aa681c1c Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Mon, 11 Jan 2021 11:05:54 +0800
Subject: [PATCH] block: don't allocate inline bvecs if this bioset needn't
bvecs
The inline bvecs won't be used if user needn't bvecs by not passing
BIOSET_NEED_BVECS, so don't allocate bvecs in this situation.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/bio.c | 7 +++++--
include/linux/bio.h | 1 +
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 87bf16460e0ead..8ccda51dd831bf 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -89,8 +89,7 @@ fail_alloc_slab:
static inline unsigned int bs_bio_slab_size(struct bio_set *bs)
{
- return bs->front_pad + sizeof(struct bio) +
- BIO_INLINE_VECS * sizeof(struct bio_vec);
+ return bs->front_pad + sizeof(struct bio) + bs->back_pad;
}
static struct kmem_cache *bio_find_or_create_slab(struct bio_set *bs)
@@ -1563,6 +1562,10 @@ int bioset_init(struct bio_set *bs,
int flags)
{
bs->front_pad = front_pad;
+ if (flags & BIOSET_NEED_BVECS)
+ bs->back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
+ else
+ bs->back_pad = 0;
spin_lock_init(&bs->rescue_lock);
bio_list_init(&bs->rescue_list);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 2f1155eabaff29..5d8977aafa199e 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -703,6 +703,7 @@ struct bio_set {
mempool_t bvec_integrity_pool;
#endif
+ unsigned int back_pad;
/*
* Deadlock avoidance for stacking block drivers: see comments in
* bio_alloc_bioset() for details
--
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