From 1b99973f1c82707e46e8cb9416865a1e955e8f8c Mon Sep 17 00:00:00 2001
From: Tao Ma <tao.ma@oracle.com>
Date: Thu, 24 Jun 2010 07:43:57 +0800
Subject: [PATCH] block: Don't count_vm_events for discard bio in submit_bio.
In submit_bio, we count vm events by check READ/WRITE.
But actually DISCARD_NOBARRIER also has the WRITE flag set.
It looks as if in blkdev_issue_discard, we also add a
page as the payload and the bio_has_data check isn't enough.
So add another check for discard bio.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---
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 3deca77e0254..f0640d7f800f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1583,7 +1583,7 @@ void submit_bio(int rw, struct bio *bio)
* If it's a regular read/write or a barrier with data attached,
* go through the normal accounting stuff before submission.
*/
- if (bio_has_data(bio)) {
+ if (bio_has_data(bio) && !(rw & (1 << BIO_RW_DISCARD))) {
if (rw & WRITE) {
count_vm_events(PGPGOUT, count);
} else {
--
GitLab