* [PATCH] block: avoid clearing blk_mq_alloc_data unnecessarily
@ 2021-12-03 15:48 Jens Axboe
2021-12-06 6:59 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2021-12-03 15:48 UTC (permalink / raw)
To: linux-block@vger.kernel.org
We already set almost all of what we need here, just the non-plug
path needs to set nr_tags and clear cached.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4dc0837f874d..eba34af1c5eb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2664,7 +2664,7 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
{
struct blk_mq_alloc_data data = {
.q = q,
- .nr_tags = 1,
+ .shallow_depth = 0
};
struct request *rq;
@@ -2683,6 +2683,9 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
data.nr_tags = plug->nr_ios;
plug->nr_ios = 1;
data.cached_rq = &plug->cached_rq;
+ } else {
+ data.nr_tags = 1;
+ data.cached_rq = NULL;
}
rq = __blk_mq_alloc_requests(&data);
--
Jens Axboe
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] block: avoid clearing blk_mq_alloc_data unnecessarily
2021-12-03 15:48 [PATCH] block: avoid clearing blk_mq_alloc_data unnecessarily Jens Axboe
@ 2021-12-06 6:59 ` Christoph Hellwig
2021-12-06 16:34 ` Jens Axboe
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2021-12-06 6:59 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-block@vger.kernel.org
On Fri, Dec 03, 2021 at 08:48:09AM -0700, Jens Axboe wrote:
> We already set almost all of what we need here, just the non-plug
> path needs to set nr_tags and clear cached.
How does this avoid clearing? All partial initializers zero the rest of
the structure.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] block: avoid clearing blk_mq_alloc_data unnecessarily
2021-12-06 6:59 ` Christoph Hellwig
@ 2021-12-06 16:34 ` Jens Axboe
0 siblings, 0 replies; 3+ messages in thread
From: Jens Axboe @ 2021-12-06 16:34 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-block@vger.kernel.org
On 12/5/21 11:59 PM, Christoph Hellwig wrote:
> On Fri, Dec 03, 2021 at 08:48:09AM -0700, Jens Axboe wrote:
>> We already set almost all of what we need here, just the non-plug
>> path needs to set nr_tags and clear cached.
>
> How does this avoid clearing? All partial initializers zero the rest of
> the structure.
Yep this is garbage, I'll just drop it.
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-12-06 16:34 UTC | newest]
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2021-12-03 15:48 [PATCH] block: avoid clearing blk_mq_alloc_data unnecessarily Jens Axboe
2021-12-06 6:59 ` Christoph Hellwig
2021-12-06 16:34 ` Jens Axboe
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