[2/7] genirq/affinity: Handle pre/post vectors in irq_calc_affinity_vectors()

From: Christogh Hellwig <hch@lst.de>

Only calculate the affinity for the main I/O vectors, and skip the
pre or post vectors specified by struct irq_affinity.

Also remove the irq_affinity cpumask argument that has never been used.
If we ever need it in the future we can pass it through struct
irq_affinity.

Signed-off-by: Christogh Hellwig <hch@lst.de>
---
 drivers/pci/msi.c         |  6 ++----
 include/linux/interrupt.h |  4 ++--
 kernel/irq/affinity.c     | 24 ++++++++++--------------
 3 files changed, 14 insertions(+), 20 deletions(-)

On 11/07/2016 07:47 PM, Christoph Hellwig wrote:
> From: Christogh Hellwig <hch@lst.de>
>
> Only calculate the affinity for the main I/O vectors, and skip the
> pre or post vectors specified by struct irq_affinity.
>
> Also remove the irq_affinity cpumask argument that has never been used.
> If we ever need it in the future we can pass it through struct
> irq_affinity.
>
> Signed-off-by: Christogh Hellwig <hch@lst.de>
> ---
>  drivers/pci/msi.c         |  6 ++----
>  include/linux/interrupt.h |  4 ++--
>  kernel/irq/affinity.c     | 24 ++++++++++--------------
>  3 files changed, 14 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index ad70507..c58d3c2 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1091,8 +1091,7 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
>
>  	for (;;) {
>  		if (affinity) {
> -			nvec = irq_calc_affinity_vectors(dev->irq_affinity,
> -					nvec);
> +			nvec = irq_calc_affinity_vectors(nvec, NULL);
>  			if (nvec < minvec)
>  				return -ENOSPC;
>  		}
> @@ -1140,8 +1139,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
>
>  	for (;;) {
>  		if (affinity) {
> -			nvec = irq_calc_affinity_vectors(dev->irq_affinity,
> -					nvec);
> +			nvec = irq_calc_affinity_vectors(nvec, NULL);
>  			if (nvec < minvec)
>  				return -ENOSPC;
>  		}
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 7284bcd..092adfb 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -291,7 +291,7 @@ extern int
>  irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
>
>  struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity, int nvec);
> -int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec);
> +int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd);
>
>  #else /* CONFIG_SMP */
>
> @@ -331,7 +331,7 @@ irq_create_affinity_masks(const struct cpumask *affinity, int nvec)
>  }
>
>  static inline int
> -irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
> +irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd)
>  {
>  	return maxvec;
>  }
> diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> index 17f51d63..8d92597 100644
> --- a/kernel/irq/affinity.c
> +++ b/kernel/irq/affinity.c
> @@ -131,24 +131,20 @@ struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
>  }
>
>  /**
> - * irq_calc_affinity_vectors - Calculate to optimal number of vectors for a given affinity mask
> - * @affinity:		The affinity mask to spread. If NULL cpu_online_mask
> - *			is used
> - * @maxvec:		The maximum number of vectors available
> + * irq_calc_affinity_vectors - Calculate the optimal number of vectors
> + * @maxvec:	The maximum number of vectors available
> + * @affd:	Description of the affinity requirements
>   */
> -int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
> +int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd)
>  {
> -	int cpus, ret;
> +	int resv = affd->pre_vectors + affd->post_vectors;
> +	int vecs = maxvec - resv;
> +	int cpus;
>
Shouldn't you check for NULL affd here?

Cheers,

Hannes

On Tue, 8 Nov 2016, Hannes Reinecke wrote:
> Shouldn't you check for NULL affd here?

No. The introduction of the default affinity struct should happen in that
patch and it should be handed down instead of NULL. Ditto for the next
patch.

Thanks,

	tglx
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