Re: [PATCH 2/4] blk-mq: introduce blk_mq_get_queue_depth()

Ming Lei
2017-05-04T02:10:23Z

On Wed, May 03, 2017 at 09:55:30AM -0700, Omar Sandoval wrote:
> On Fri, Apr 28, 2017 at 11:15:37PM +0800, Ming Lei wrote:
> > The hardware queue depth can be resized via blk_mq_update_nr_requests(),
> > so introduce this helper for retrieving queue's depth easily.
>
> One nit below. If the per-hardware queue tag space situation changes, we
> can revisit this and the similar thing in Kyber.

OK, will add comment about this situation in V3.

>
> Reviewed-by: Omar Sandoval <osandov@fb.com>
>
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> > block/blk-mq.c | 12 ++++++++++++
> > block/blk-mq.h | 1 +
> > 2 files changed, 13 insertions(+)
> >
> > diff --git a/block/blk-mq.c b/block/blk-mq.c
> > index e530bc54f0d9..04761fb76ab4 100644
> > --- a/block/blk-mq.c
> > +++ b/block/blk-mq.c
> > @@ -2637,6 +2637,18 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
> > }
> > EXPORT_SYMBOL(blk_mq_free_tag_set);
> >
> > +/*
> > + * Queue depth can be changed via blk_mq_update_nr_requests(),
> > + * so use this helper to retrieve queue's depth.
> > + */
> > +int blk_mq_get_queue_depth(struct request_queue *q)
> > +{
> > + /* All queues have same queue depth */
> > + struct blk_mq_tags *tags = q->tag_set->tags[0];
>
> Not sure what's going on with the spacing here. Tab instead of a space?

Either one should be fine, and I am sure this patch is warning/error
free when checking with ./scripts/checkpatch.pl, :-)

Thanks,
Ming