Re: [PATCH 06/12] blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()

[Christoph Hellwig]

On Wed, Oct 26, 2016 at 03:53:39PM -0700, Bart Van Assche wrote:
> Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
> are followed by kicking the requeue list. Hence add an argument to
> these two functions that allows to kick the requeue list. This was
> proposed by Christoph Hellwig.

Looks good,

Reviewed-by: Christoph Hellwig 
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 06/12] blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()

[Johannes Thumshirn]

On Wed, Oct 26, 2016 at 03:53:39PM -0700, Bart Van Assche wrote:
> Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
> are followed by kicking the requeue list. Hence add an argument to
> these two functions that allows to kick the requeue list. This was
> proposed by Christoph Hellwig.
> 
> Signed-off-by: Bart Van Assche 
> Cc: Christoph Hellwig 

Looks good,
Reviewed-by: Johannes Thumshirn 

-- 
Johannes Thumshirn  Storage
jthumsh...@suse.de+49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 06/12] blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()

[Hannes Reinecke]

On 10/27/2016 12:53 AM, Bart Van Assche wrote:
> Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
> are followed by kicking the requeue list. Hence add an argument to
> these two functions that allows to kick the requeue list. This was
> proposed by Christoph Hellwig.
> 
> Signed-off-by: Bart Van Assche 
> Cc: Christoph Hellwig 
> Cc: Hannes Reinecke 
> Cc: Sagi Grimberg 
> Cc: Johannes Thumshirn 
> ---
>  block/blk-flush.c|  5 +
>  block/blk-mq.c   | 10 +++---
>  drivers/block/xen-blkfront.c |  2 +-
>  drivers/md/dm-rq.c   |  2 +-
>  drivers/nvme/host/core.c |  2 +-
>  drivers/scsi/scsi_lib.c  |  4 +---
>  include/linux/blk-mq.h   |  5 +++--
>  7 files changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/block/blk-flush.c b/block/blk-flush.c
> index 6a14b68..a834aed 100644
> --- a/block/blk-flush.c
> +++ b/block/blk-flush.c
> @@ -134,10 +134,7 @@ static void blk_flush_restore_request(struct request *rq)
>  static bool blk_flush_queue_rq(struct request *rq, bool add_front)
>  {
>   if (rq->q->mq_ops) {
> - struct request_queue *q = rq->q;
> -
> - blk_mq_add_to_requeue_list(rq, add_front);
> - blk_mq_kick_requeue_list(q);
> + blk_mq_add_to_requeue_list(rq, add_front, true);
>   return false;
>   } else {
>   if (add_front)
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 4945437..688bcc3 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -492,12 +492,12 @@ static void __blk_mq_requeue_request(struct request *rq)
>   }
>  }
>  
> -void blk_mq_requeue_request(struct request *rq)
> +void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
>  {
>   __blk_mq_requeue_request(rq);
>  
>   BUG_ON(blk_queued_rq(rq));
> - blk_mq_add_to_requeue_list(rq, true);
> + blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
>  }
>  EXPORT_SYMBOL(blk_mq_requeue_request);
>  
> @@ -535,7 +535,8 @@ static void blk_mq_requeue_work(struct work_struct *work)
>   blk_mq_start_hw_queues(q);
>  }
>  
> -void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
> +void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
> + bool kick_requeue_list)
>  {
>   struct request_queue *q = rq->q;
>   unsigned long flags;
> @@ -554,6 +555,9 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool 
> at_head)
>   list_add_tail(>queuelist, >requeue_list);
>   }
>   spin_unlock_irqrestore(>requeue_lock, flags);
> +
> + if (kick_requeue_list)
> + blk_mq_kick_requeue_list(q);
>  }
>  EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
>  
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 9908597..1ca702d 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -2043,7 +2043,7 @@ static int blkif_recover(struct blkfront_info *info)
>   /* Requeue pending requests (flush or discard) */
>   list_del_init(>queuelist);
>   BUG_ON(req->nr_phys_segments > segs);
> - blk_mq_requeue_request(req);
> + blk_mq_requeue_request(req, false);
>   }
>   blk_mq_kick_requeue_list(info->rq);
>  
> diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
> index dc75bea..fbd37b4 100644
> --- a/drivers/md/dm-rq.c
> +++ b/drivers/md/dm-rq.c
> @@ -354,7 +354,7 @@ EXPORT_SYMBOL(dm_mq_kick_requeue_list);
>  
>  static void dm_mq_delay_requeue_request(struct request *rq, unsigned long 
> msecs)
>  {
> - blk_mq_requeue_request(rq);
> + blk_mq_requeue_request(rq, false);
>   __dm_mq_kick_requeue_list(rq->q, msecs);
>  }
>  
Hmm. __dm_mq_kick_requeue_list() does essentially the same.
Have you checked if you can use 'true' here and drop the call to it?
However, it does take the queue_lock when doing so.
Is that required? None of the other drivers do it ...

Cheers,

Hannes
-- 
Dr. Hannes ReineckeTeamlead Storage & Networking
h...@suse.de   +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html