* [PATCH] blk-mq: fix blk_mq_start_stopped_hw_queues from irq context
@ 2013-10-06 17:09 Christoph Hellwig
2013-10-06 18:10 ` Jens Axboe
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2013-10-06 17:09 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-kernel
The only caller of blk_mq_start_stopped_hw_queues is in irq context,
leading to lockdep splat when it actually gets called. Fix this by
deferring the hw queue run to workqueue context.
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2b85029..923e9e1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -686,7 +686,8 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q)
if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
continue;
- blk_mq_start_hw_queue(hctx);
+ clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+ blk_mq_run_hw_queue(hctx, true);
}
}
EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] blk-mq: fix blk_mq_start_stopped_hw_queues from irq context
2013-10-06 17:09 [PATCH] blk-mq: fix blk_mq_start_stopped_hw_queues from irq context Christoph Hellwig
@ 2013-10-06 18:10 ` Jens Axboe
2013-10-07 19:33 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2013-10-06 18:10 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-kernel
On Sun, Oct 06 2013, Christoph Hellwig wrote:
> The only caller of blk_mq_start_stopped_hw_queues is in irq context,
> leading to lockdep splat when it actually gets called. Fix this by
> deferring the hw queue run to workqueue context.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 2b85029..923e9e1 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -686,7 +686,8 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q)
> if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
> continue;
>
> - blk_mq_start_hw_queue(hctx);
> + clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
> + blk_mq_run_hw_queue(hctx, true);
> }
> }
> EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
Thanks, applied. Might not be a bad idea to just mimic the run queue
API, and provide a blk_mq_start_hw_queue(hctx, is_async) instead.
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] blk-mq: fix blk_mq_start_stopped_hw_queues from irq context
2013-10-06 18:10 ` Jens Axboe
@ 2013-10-07 19:33 ` Christoph Hellwig
0 siblings, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2013-10-07 19:33 UTC (permalink / raw)
To: Jens Axboe; +Cc: Christoph Hellwig, linux-kernel
On Sun, Oct 06, 2013 at 12:10:13PM -0600, Jens Axboe wrote:
> Thanks, applied. Might not be a bad idea to just mimic the run queue
> API, and provide a blk_mq_start_hw_queue(hctx, is_async) instead.
I have to see I really don't like this is_async, I'd much preper to
untangle those into separate versions further up the stack similar to
how the old blk_run_queue variants work.
But that'll have to wait a bit anyway, at least until you made a
decision on the plugging patch.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-10-07 19:34 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2013-10-06 17:09 [PATCH] blk-mq: fix blk_mq_start_stopped_hw_queues from irq context Christoph Hellwig
2013-10-06 18:10 ` Jens Axboe
2013-10-07 19:33 ` Christoph Hellwig
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