diff mbox

[3/7] block: use appropriate queue running functions

Message ID 1480734921-23701-4-git-send-email-axboe@fb.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jens Axboe Dec. 3, 2016, 3:15 a.m. UTC 
Use MQ variants for MQ, legacy ones for legacy.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-core.c  |  5 ++++-
 block/blk-exec.c  | 10 ++++++++--
 block/blk-flush.c | 14 ++++++++++----
 block/elevator.c  |  5 ++++-
 4 files changed, 26 insertions(+), 8 deletions(-)

Comments

Johannes Thumshirn Dec. 5, 2016, 9:01 a.m. UTC | #1 
On Fri, Dec 02, 2016 at 08:15:17PM -0700, Jens Axboe wrote:
> Use MQ variants for MQ, legacy ones for legacy.
> 
> Signed-off-by: Jens Axboe <axboe@fb.com>
> ---
>  block/blk-core.c  |  5 ++++-
>  block/blk-exec.c  | 10 ++++++++--
>  block/blk-flush.c | 14 ++++++++++----
>  block/elevator.c  |  5 ++++-
>  4 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 0e23589ab3bf..3591f5419509 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -340,7 +340,10 @@ void __blk_run_queue(struct request_queue *q)
>  	if (unlikely(blk_queue_stopped(q)))
>  		return;
>  
> -	__blk_run_queue_uncond(q);

I don't quite get the WARN_ON_ONCE() is it for debug purposes? And similarly
blk_use_mq_path() + the other occurences below as well?
Christoph Hellwig Dec. 5, 2016, 1:07 p.m. UTC | #2 
On Fri, Dec 02, 2016 at 08:15:17PM -0700, Jens Axboe wrote:
> Use MQ variants for MQ, legacy ones for legacy.
> 
> Signed-off-by: Jens Axboe <axboe@fb.com>
> ---
>  block/blk-core.c  |  5 ++++-
>  block/blk-exec.c  | 10 ++++++++--
>  block/blk-flush.c | 14 ++++++++++----
>  block/elevator.c  |  5 ++++-
>  4 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 0e23589ab3bf..3591f5419509 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -340,7 +340,10 @@ void __blk_run_queue(struct request_queue *q)
>  	if (unlikely(blk_queue_stopped(q)))
>  		return;
>  
> -	__blk_run_queue_uncond(q);
> +	if (WARN_ON_ONCE(q->mq_ops))
> +		blk_mq_run_hw_queues(q, true);
> +	else

This looks odd with the WARN_ON..

> +++ b/block/blk-exec.c
> @@ -80,8 +80,14 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
>  	}
>  
>  	__elv_add_request(q, rq, where);
> -	__blk_run_queue(q);
> -	spin_unlock_irq(q->queue_lock);
> +
> +	if (q->mq_ops) {
> +		spin_unlock_irq(q->queue_lock);
> +		blk_mq_run_hw_queues(q, false);
> +	} else {
> +		__blk_run_queue(q);
> +		spin_unlock_irq(q->queue_lock);
> +	}

We already branch out to the blk-mq path earlier in the function.
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Jens Axboe Dec. 5, 2016, 3:10 p.m. UTC | #3 
On 12/05/2016 06:07 AM, Christoph Hellwig wrote:
> On Fri, Dec 02, 2016 at 08:15:17PM -0700, Jens Axboe wrote:
>> Use MQ variants for MQ, legacy ones for legacy.
>>
>> Signed-off-by: Jens Axboe <axboe@fb.com>
>> ---
>>  block/blk-core.c  |  5 ++++-
>>  block/blk-exec.c  | 10 ++++++++--
>>  block/blk-flush.c | 14 ++++++++++----
>>  block/elevator.c  |  5 ++++-
>>  4 files changed, 26 insertions(+), 8 deletions(-)
>>
>> diff --git a/block/blk-core.c b/block/blk-core.c
>> index 0e23589ab3bf..3591f5419509 100644
>> --- a/block/blk-core.c
>> +++ b/block/blk-core.c
>> @@ -340,7 +340,10 @@ void __blk_run_queue(struct request_queue *q)
>>  	if (unlikely(blk_queue_stopped(q)))
>>  		return;
>>  
>> -	__blk_run_queue_uncond(q);
>> +	if (WARN_ON_ONCE(q->mq_ops))
>> +		blk_mq_run_hw_queues(q, true);
>> +	else
> 
> This looks odd with the WARN_ON..

It's just a debug thing, should go away.

>> +++ b/block/blk-exec.c
>> @@ -80,8 +80,14 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
>>  	}
>>  
>>  	__elv_add_request(q, rq, where);
>> -	__blk_run_queue(q);
>> -	spin_unlock_irq(q->queue_lock);
>> +
>> +	if (q->mq_ops) {
>> +		spin_unlock_irq(q->queue_lock);
>> +		blk_mq_run_hw_queues(q, false);
>> +	} else {
>> +		__blk_run_queue(q);
>> +		spin_unlock_irq(q->queue_lock);
>> +	}
> 
> We already branch out to the blk-mq path earlier in the function.

Ah good point, this is a subset of an earlier branch that also checks
q->elevator.
Jens Axboe Dec. 5, 2016, 5:39 p.m. UTC | #4 
On 12/05/2016 08:10 AM, Jens Axboe wrote:
> On 12/05/2016 06:07 AM, Christoph Hellwig wrote:
>> On Fri, Dec 02, 2016 at 08:15:17PM -0700, Jens Axboe wrote:
>>> Use MQ variants for MQ, legacy ones for legacy.
>>>
>>> Signed-off-by: Jens Axboe <axboe@fb.com>
>>> ---
>>>  block/blk-core.c  |  5 ++++-
>>>  block/blk-exec.c  | 10 ++++++++--
>>>  block/blk-flush.c | 14 ++++++++++----
>>>  block/elevator.c  |  5 ++++-
>>>  4 files changed, 26 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/block/blk-core.c b/block/blk-core.c
>>> index 0e23589ab3bf..3591f5419509 100644
>>> --- a/block/blk-core.c
>>> +++ b/block/blk-core.c
>>> @@ -340,7 +340,10 @@ void __blk_run_queue(struct request_queue *q)
>>>  	if (unlikely(blk_queue_stopped(q)))
>>>  		return;
>>>  
>>> -	__blk_run_queue_uncond(q);
>>> +	if (WARN_ON_ONCE(q->mq_ops))
>>> +		blk_mq_run_hw_queues(q, true);
>>> +	else
>>
>> This looks odd with the WARN_ON..
> 
> It's just a debug thing, should go away.
> 
>>> +++ b/block/blk-exec.c
>>> @@ -80,8 +80,14 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
>>>  	}
>>>  
>>>  	__elv_add_request(q, rq, where);
>>> -	__blk_run_queue(q);
>>> -	spin_unlock_irq(q->queue_lock);
>>> +
>>> +	if (q->mq_ops) {
>>> +		spin_unlock_irq(q->queue_lock);
>>> +		blk_mq_run_hw_queues(q, false);
>>> +	} else {
>>> +		__blk_run_queue(q);
>>> +		spin_unlock_irq(q->queue_lock);
>>> +	}
>>
>> We already branch out to the blk-mq path earlier in the function.
> 
> Ah good point, this is a subset of an earlier branch that also checks
> q->elevator.

Actually, I take that back - if q->mq_ops && q->elevator, we still get
here, and we should run the queue with the MQ variant. The code was
correct as-is.
diff mbox

Patch

diff --git a/block/blk-core.c b/block/blk-core.c
index 0e23589ab3bf..3591f5419509 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -340,7 +340,10 @@  void __blk_run_queue(struct request_queue *q)
 	if (unlikely(blk_queue_stopped(q)))
 		return;
 
-	__blk_run_queue_uncond(q);
+	if (WARN_ON_ONCE(q->mq_ops))
+		blk_mq_run_hw_queues(q, true);
+	else
+		__blk_run_queue_uncond(q);
 }
 EXPORT_SYMBOL(__blk_run_queue);
 
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 73b8a701ae6d..27e4d82564ed 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -80,8 +80,14 @@  void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 	}
 
 	__elv_add_request(q, rq, where);
-	__blk_run_queue(q);
-	spin_unlock_irq(q->queue_lock);
+
+	if (q->mq_ops) {
+		spin_unlock_irq(q->queue_lock);
+		blk_mq_run_hw_queues(q, false);
+	} else {
+		__blk_run_queue(q);
+		spin_unlock_irq(q->queue_lock);
+	}
 }
 EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
 
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 0b68a1258bdd..620d69909b8d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -265,8 +265,10 @@  static void flush_end_io(struct request *flush_rq, int error)
 	 * kblockd.
 	 */
 	if (queued || fq->flush_queue_delayed) {
-		WARN_ON(q->mq_ops);
-		blk_run_queue_async(q);
+		if (q->mq_ops)
+			blk_mq_run_hw_queues(q, true);
+		else
+			blk_run_queue_async(q);
 	}
 	fq->flush_queue_delayed = 0;
 	if (blk_use_mq_path(q))
@@ -346,8 +348,12 @@  static void flush_data_end_io(struct request *rq, int error)
 	 * After populating an empty queue, kick it to avoid stall.  Read
 	 * the comment in flush_end_io().
 	 */
-	if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error))
-		blk_run_queue_async(q);
+	if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error)) {
+		if (q->mq_ops)
+			blk_mq_run_hw_queues(q, true);
+		else
+			blk_run_queue_async(q);
+	}
 }
 
 static void mq_flush_data_end_io(struct request *rq, int error)
diff --git a/block/elevator.c b/block/elevator.c
index a18a5db274e4..11d2cfee2bc1 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -627,7 +627,10 @@  void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 		 *   with anything.  There's no point in delaying queue
 		 *   processing.
 		 */
-		__blk_run_queue(q);
+		if (q->mq_ops)
+			blk_mq_run_hw_queues(q, true);
+		else
+			__blk_run_queue(q);
 		break;
 
 	case ELEVATOR_INSERT_SORT_MERGE: