Request cloning clones bios in the request to track the completion
of each bio.
For that purpose, we can use bio_clone_fast() instead of bio_clone()
to avoid unnecessary allocation and copy of bvecs.
This patch reduces memory footprint of request-based device-mapper
(about 1-4KB for each request) and is a preparation for further
reduction of memory usage by removing unused bvec mempool.
Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx>
---
block/blk-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index bf930f4..a92f720 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2931,7 +2931,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
blk_rq_init(NULL, rq);
__rq_for_each_bio(bio_src, rq_src) {
- bio = bio_clone_bioset(bio_src, gfp_mask, bs);
+ bio = bio_clone_fast(bio_src, gfp_mask, bs);
if (!bio)
goto free_and_out;
--
1.9.3
--
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