Last post of this patch appears lost, so I resend this.
Now discard merge works, add plug for blkdev_issue_discard. This will help
discard request merge especially for raid0 case. In raid0, a big discard
request is split to small requests, and if correct plug is added, such small
requests can be merged in low layer.
Signed-off-by: Shaohua Li <s...@fusionio.com>
---
block/blk-lib.c | 3 +++
1 file changed, 3 insertions(+)
Index: linux/block/blk-lib.c
===================================================================
--- linux.orig/block/blk-lib.c 2012-12-14 10:03:22.305422686 +0800
+++ linux/block/blk-lib.c 2012-12-14 10:08:50.577295672 +0800
@@ -48,6 +48,7 @@ int blkdev_issue_discard(struct block_de
struct bio_batch bb;
struct bio *bio;
int ret = 0;
+ struct blk_plug plug;
if (!q)
return -ENXIO;
@@ -82,6 +83,7 @@ int blkdev_issue_discard(struct block_de
bb.flags = 1 << BIO_UPTODATE;
bb.wait = &wait;
+ blk_start_plug(&plug);
while (nr_sects) {
unsigned int req_sects;
sector_t end_sect, tmp;
@@ -120,6 +122,7 @@ int blkdev_issue_discard(struct block_de
atomic_inc(&bb.done);
submit_bio(type, bio);
}
+ blk_finish_plug(&plug);
/* Wait for bios in-flight */
if (!atomic_dec_and_test(&bb.done))
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
