Messages in this thread | | | Date | Wed, 2 Nov 2016 15:59:08 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH 5/8] block: add code to track actual device queue depth |
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On Tue, Nov 01, 2016 at 03:08:48PM -0600, Jens Axboe wrote: > For blk-mq, ->nr_requests does track queue depth, at least at init > time. But for the older queue paths, it's simply a soft setting. > On top of that, it's generally larger than the hardware setting > on purpose, to allow backup of requests for merging. > > Fill a hole in struct request with a 'queue_depth' member, that
That would be struct request_queue..
> /** > + * blk_set_queue_depth - tell the block layer about the device queue depth > + * @q: the request queue for the device > + * @depth: queue depth > + * > + */ > +void blk_set_queue_depth(struct request_queue *q, unsigned int depth) > +{ > + q->queue_depth = depth; > +} > +EXPORT_SYMBOL(blk_set_queue_depth);
Do we really need this wrapper?
> +++ b/drivers/scsi/scsi.c > @@ -621,6 +621,9 @@ int scsi_change_queue_depth(struct scsi_device *sdev, int depth) > wmb(); > } > > + if (sdev->request_queue) > + blk_set_queue_depth(sdev->request_queue, depth); > + > return sdev->queue_depth;
Can we kill the scsi_device queue_depth member and just always use the request_queue one?
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