Re: [PATCH 1/7] genirq/affinity: Introduce struct irq_affinity

[Hannes Reinecke]

On 11/07/2016 07:47 PM, Christoph Hellwig wrote:
> From: Christogh Hellwig <hch@xxxxxx>
>
> Some drivers (various network and RDMA adapter for example) have a MSI-X
> vector layout where most of the vectors are used for I/O queues and should
> have CPU affinity assigned to them, but some (usually 1 but sometimes more)
> at the beginning or end are used for low-performance admin or configuration
> work and should not have any explicit affinity assigned to them.
>
> This adds a new irq_affinity structure, which will be passed through a
> variant of pci_irq_alloc_vectors that allows to specify these
> requirements (and is extensible to any future quirks in that area) so that
> the core IRQ affinity algorithm can take this quirks into account.
>
> Signed-off-by: Christogh Hellwig <hch@xxxxxx>
> ---
>  include/linux/interrupt.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 72f0721..7284bcd 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -232,6 +232,18 @@ struct irq_affinity_notify {
>  	void (*release)(struct kref *ref);
>  };
>
> +/**
> + * struct irq_affinity - Description for auto irq affinity assignements
> + * @pre_vectors:	Reserved vectors at the beginning of the MSIX
> + *			vector space
> + * @post_vectors:	Reserved vectors at the end of the MSIX
> + *			vector space
> + */
> +struct irq_affinity {
> +	int	pre_vectors;
> +	int	post_vectors;
> +};
> +
>  #if defined(CONFIG_SMP)
>
>  extern cpumask_var_t irq_default_affinity;
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke		   Teamlead Storage & Networking
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