2012-08-09 05:28:18

by Shaohua Li

Subject: [RFC]block: disable discard request merge temporarily

The SCSI discard request merge never worked, and looks no solution for in
future, let's disable it temporarily.

Signed-off-by: Shaohua Li <[email protected]>

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4e72a9d..0e6efb1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -601,7 +601,7 @@ static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
+ (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_DISCARD)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
(((rq)->cmd_flags & REQ_DISCARD) || \

2012-08-09 07:45:43

by Christoph Hellwig

Subject: Re: [RFC]block: disable discard request merge temporarily

On Thu, Aug 09, 2012 at 01:28:03PM +0800, Shaohua Li wrote:
> The SCSI discard request merge never worked, and looks no solution for in
> future, let's disable it temporarily.
>
> Signed-off-by: Shaohua Li <[email protected]>

Looks good and is equivalent to what I proposed over a year aggo,

Reviewed-by: Christoph Hellwig <[email protected]>

2012-08-09 13:20:28

by Jens Axboe

Subject: Re: [RFC]block: disable discard request merge temporarily

On 08/09/2012 07:28 AM, Shaohua Li wrote:
> The SCSI discard request merge never worked, and looks no solution for in
> future, let's disable it temporarily.

Thanks, applied!

--
Jens Axboe