Re: [PATCH 11/13] blk-mq: allow the driver to pass in an affinity mask

From: Alexander Gordeev
Date: Tue Jul 12 2016 - 02:37:47 EST


On Sun, Jul 10, 2016 at 05:41:44AM +0200, Christoph Hellwig wrote:
> On Mon, Jul 04, 2016 at 11:35:28AM +0200, Alexander Gordeev wrote:
> > > mq_map is initialized to zero already, so we don't really need the
> > > assignment for queue 0. The reason why this check exists is because
> > > we start with queue = -1 and we never want to assignment -1 to mq_map.
> >
> > Would this read better then?
> >
> > int queue = 0;
> >
> > ...
> >
> > /* If cpus are offline, map them to first hctx */
> > for_each_online_cpu(cpu) {
> > set->mq_map[cpu] = queue;
> > if (cpumask_test_cpu(cpu, affinity_mask))
> > queue++;
>
> It would read better, but I don't think it's actually correct.
> We'd still assign the 'old' queue to the cpu that is set in the affinity
> mask.

To be honest, I fail to see a functional difference, but it is just
a nit anyway.