Re: [PATCH RESEND 0/1] AHCI: Optimize interrupt processing

From: Alexander Gordeev
Date: Fri Aug 09 2013 - 12:47:40 EST


On Fri, Aug 09, 2013 at 09:52:19AM -0600, Jens Axboe wrote:
> On 08/09/2013 09:07 AM, Alexander Gordeev wrote:
> > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
> > index dcbc2a4..b131a48 100644
> > --- a/block/blk-mq-tag.c
> > +++ b/block/blk-mq-tag.c
> > @@ -468,10 +468,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
> > * Rest of the tags start at the queue list
> > */
> > tags->nr_free = 0;
> > - while (nr_tags - tags->nr_reserved) {
> > + while (nr_tags--) {
> > tags->freelist[tags->nr_free] = tags->nr_free +
> > tags->nr_reserved;
> > - nr_tags--;
> > tags->nr_free++;
> > }
>
> I misremembered, just checked the code. I think I used to have it like I
> described, but changed it since I thought it would be more logical to
> pass in full depth, and then what part of that is reserved. Looking at
> the current code, your patch looks correct as-is.

Ok, then a whole series "[PATCH 0/3] blk-mq: Avoid effects of a weird queue
depth" (I posted earlier in a separate thread) should make sense. Besides
the hunk above it limits the per-cpu cache size and sanity-checks total vs
reserved length. I can resubmit if you want.

>
> --
> Jens Axboe
>

--
Regards,
Alexander Gordeev
agordeev@xxxxxxxxxx
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