Re: [PATCH 5/5] blk-mq: Drop 'reserved' member of busy_tag_iter_fn

[John Garry]

On 17/06/2022 17:33, Bart Van Assche wrote:
> On 6/17/22 03:55, John Garry wrote:
> > We no longer use the 'reserved' member in for any iter function so it
>                                           ^^^^^^
> One of these two words probably should be removed.

Yeah, it's a typo - I can fix it.

> > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
> > index 2dcd738c6952..b8cc8b41553f 100644
> > --- a/block/blk-mq-tag.c
> > +++ b/block/blk-mq-tag.c
> > @@ -266,7 +266,6 @@ static bool bt_iter(struct sbitmap *bitmap, 
> > unsigned int bitnr, void *data)
> >       struct blk_mq_hw_ctx *hctx = iter_data->hctx;
> >       struct request_queue *q = iter_data->q;
> >       struct blk_mq_tag_set *set = q->tag_set;
> > -    bool reserved = iter_data->reserved;
> >       struct blk_mq_tags *tags;
> >       struct request *rq;
> >       bool ret = true;
> > @@ -276,7 +275,7 @@ static bool bt_iter(struct sbitmap *bitmap, 
> > unsigned int bitnr, void *data)
> >       else
> >           tags = hctx->tags;
> > -    if (!reserved)
> > +    if (!iter_data->reserved)
> >           bitnr += tags->nr_reserved_tags;
> >       /*
> >        * We can hit rq == NULL here, because the tagging functions
>
> Is the above change really necessary?

It's not totally necessary. Since local variable 'reserved' would now 
only be used once I thought it was better to get rid of it.

I can keep it if you really think that is better.

> > @@ -337,12 +336,11 @@ static bool bt_tags_iter(struct sbitmap *bitmap, 
> > unsigned int bitnr, void *data)
> >   {
> >       struct bt_tags_iter_data *iter_data = data;
> >       struct blk_mq_tags *tags = iter_data->tags;
> > -    bool reserved = iter_data->flags & BT_TAG_ITER_RESERVED;
> >       struct request *rq;
> >       bool ret = true;
> >       bool iter_static_rqs = !!(iter_data->flags & 
> > BT_TAG_ITER_STATIC_RQS);
> > -    if (!reserved)
> > +    if (!(iter_data->flags & BT_TAG_ITER_RESERVED))
> >           bitnr += tags->nr_reserved_tags;
> >       /*
>
> Same question here: is the above change really necessary?

As above.

Thanks,
john