Re: irq/affinity: Fix extra vecs calculation

From: Keith Busch
Date: Wed Apr 19 2017 - 18:36:52 EST


On Wed, Apr 19, 2017 at 03:32:06PM -0700, Andrei Vagin wrote:
> This patch works for me.

Awesome, thank you much for confirming, and again, sorry for the
breakage. I see virtio-scsi is one reliable way to have reproduced this,
so I'll incorporate that into tests before posting future kernel core
patches.

I'll send this fix with change log shortly.

> > ---
> > diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> > index d052947..eb8b689 100644
> > --- a/kernel/irq/affinity.c
> > +++ b/kernel/irq/affinity.c
> > @@ -98,13 +98,16 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
> > int ncpus, v, vecs_to_assign, vecs_per_node;
> >
> > /* Spread the vectors per node */
> > - vecs_per_node = (affv - curvec) / nodes;
> > + vecs_per_node = (affv - (curvec - affd->pre_vectors)) / nodes;
> >
> > /* Get the cpus on this node which are in the mask */
> > cpumask_and(nmsk, cpu_online_mask, cpumask_of_node(n));
> > --