Re: [tip:irq/urgent] genirq/affinity: Fix calculating vectors to assign

[Andrei Vagin <avagin@virtuozzo.com>]

Looks like 4.11 will be release in a few days, it would be nice if this
commit reaches the upstream tree before this moment.

Thanks.

On Thu, Apr 20, 2017 at 07:06:49AM -0700, tip-bot for Keith Busch wrote:
> Commit-ID:  b72f8051f34b8164a62391e3676edc34523c5952
> Gitweb:     http://git.kernel.org/tip/b72f8051f34b8164a62391e3676edc34523c5952
> Author:     Keith Busch <keith.busch@intel.com>
> AuthorDate: Wed, 19 Apr 2017 19:51:10 -0400
> Committer:  Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Thu, 20 Apr 2017 16:03:09 +0200
> 
> genirq/affinity: Fix calculating vectors to assign
> 
> The vectors_per_node is calculated from the remaining available vectors.
> The current vector starts after pre_vectors, so we need to subtract that
> from the current to properly account for the number of remaining vectors
> to assign.
> 
> Fixes: 3412386b531 ("irq/affinity: Fix extra vecs calculation")
> Reported-by: Andrei Vagin <avagin@virtuozzo.com>
> Signed-off-by: Keith Busch <keith.busch@intel.com>
> Link: http://lkml.kernel.org/r/1492645870-13019-1-git-send-email-keith.busch@intel.com
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 
> ---
>  kernel/irq/affinity.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> index d052947..e2d356d 100644
> --- a/kernel/irq/affinity.c
> +++ b/kernel/irq/affinity.c
> @@ -98,7 +98,7 @@ 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));