[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>
diff --git a/fs/bio.c b/fs/bio.c
index 8f93e93..f95c874 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -79,7 +79,6 @@
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 @@
* 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 @@
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)) {