* [PATCH] blk-mq: cache rq->q
@ 2013-10-11 4:11 Shaohua Li
2013-10-11 14:25 ` Jens Axboe
0 siblings, 1 reply; 2+ messages in thread
From: Shaohua Li @ 2013-10-11 4:11 UTC (permalink / raw)
To: linux-kernel, axboe
If a tag is freed, the request might be used very soon. There is a short window
rq->q is null, so cache it.
Signed-off-by: Shaohua Li <shli@fusionio.com>
---
block/blk-mq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: master/block/blk-mq.c
===================================================================
--- master.orig/block/blk-mq.c 2013-10-11 12:07:32.282133638 +0800
+++ master/block/blk-mq.c 2013-10-11 12:07:32.282133638 +0800
@@ -250,11 +250,12 @@ static void __blk_mq_free_request(struct
struct blk_mq_ctx *ctx, struct request *rq)
{
const int tag = rq->tag;
+ struct request_queue *q = rq->q;
blk_mq_rq_init(hctx, rq);
blk_mq_put_tag(hctx->tags, tag);
- blk_mq_queue_exit(rq->q);
+ blk_mq_queue_exit(q);
}
void blk_mq_free_request(struct request *rq)
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] blk-mq: cache rq->q
2013-10-11 4:11 [PATCH] blk-mq: cache rq->q Shaohua Li
@ 2013-10-11 14:25 ` Jens Axboe
0 siblings, 0 replies; 2+ messages in thread
From: Jens Axboe @ 2013-10-11 14:25 UTC (permalink / raw)
To: Shaohua Li, linux-kernel
On 10/10/2013 10:11 PM, Shaohua Li wrote:
>
> If a tag is freed, the request might be used very soon. There is a short window
> rq->q is null, so cache it.
Thanks, good catch! Applied.
--
Jens Axboe
^ permalink raw reply [flat|nested] 2+ messages in thread
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2013-10-11 14:25 ` Jens Axboe
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