From bf02c082bf7a464518d45b9c178b8aa83f74dd5d Mon Sep 17 00:00:00 2001
From: Andreas Mohr <andi@rhlx01.fht-esslingen.de>
Date: Wed, 11 Oct 2006 01:22:24 -0700
Subject: [PATCH] [PATCH] fs/bio.c: tweaks
- Calculate a variable in bvec_alloc_bs() only once needed, not earlier
(bio.o down from 18408 to 18376 Bytes, 32 Bytes saved, probably due to
data locality improvements).
- Init variable idx to silence a gcc warning which already existed in the
unmodified original base file (bvec_alloc_bs() handles idx correctly, so
there's no need for the warning):
fs/bio.c: In function `bio_alloc_bioset':
fs/bio.c:169: warning: `idx' may be used uninitialized in this function
Signed-off-by: Andreas Mohr <andi@lisas.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
fs/bio.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fs/bio.c b/fs/bio.c
index 8f93e939f2137..f95c8749499f9 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -79,7 +79,6 @@ static struct bio_set *fs_bio_set;
static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs)
{
struct bio_vec *bvl;
- struct biovec_slab *bp;
/*
* see comment near bvec_array define!
@@ -98,10 +97,12 @@ static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned lon
* idx now points to the pool we want to allocate from
*/
- bp = bvec_slabs + *idx;
bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask);
- if (bvl)
+ if (bvl) {
+ struct biovec_slab *bp = bvec_slabs + *idx;
+
memset(bvl, 0, bp->nr_vecs * sizeof(struct bio_vec));
+ }
return bvl;
}
@@ -166,7 +167,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
bio_init(bio);
if (likely(nr_iovecs)) {
- unsigned long idx;
+ unsigned long idx = 0; /* shut up gcc */
bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
if (unlikely(!bvl)) {
--
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