Re: [PATCH v2 06/11] blk-mq: Pass driver tags to blk_mq_clear_rq_mapping()

Ming Lei
2021-08-23T02:59:55Z

On Thu, Aug 19, 2021 at 08:32:20AM +0100, John Garry wrote:
> On 19/08/2021 01:39, Ming Lei wrote:
> > > That's intentional, as we have from later patch:
> > >
> > > void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
> > > unsigned int hctx_idx)
> > > {
> > > struct blk_mq_tags *drv_tags;
> > > struct page *page;
> > >
> > > + if (blk_mq_is_sbitmap_shared(set->flags))
> > > + drv_tags = set->shared_sbitmap_tags;
> > > + else
> > > drv_tags = set->tags[hctx_idx];
> > >
> > > ...
> > >
> > > blk_mq_clear_rq_mapping(drv_tags, tags);
> > >
> > > }
> > >
> > > And it's just nice to not re-indent later.
> > But this way is weird, and I don't think checkpatch.pl is happy with
> > it.
>
> There is the idea to try to not remove/change code earlier in a series - I
> am taking it to an extreme! I can stop.
>
> On another related topic, how about this change also:
>
> ---8<---
> void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
> struct blk_mq_tags *tags)
> {
>
> + /* There is no need to clear a driver tags own mapping */
> + if (drv_tags == tags)
> + return;
> --->8---

The change itself is correct, and no need to clear driver tags
->rq[] since all request queues have been cleaned up when freeing
tagset.

Thanks,
Ming