Re: [PATCH] [genirq] Expose default irq affinity mask

[Randy Dunlap <rdunlap@xenotime.net>]

On Fri, 23 May 2008 12:46:35 -0700 Max Krasnyansky wrote:

> Current IRQ affinity interface does not provide a way to set affinity
> for the IRQs that will be allocated/activated in the future.
> This patch creates /proc/irq/default_smp_affinity that lets users set
> default affinity mask for the newly allocated IRQs. Changing default
> does not affect affinity masks for the currently active IRQs, they
> have to be changed explicitly.

Documentation, perhaps an update to Documentation/filesystems/proc.txt ?

> Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
> ---
>  arch/alpha/kernel/irq.c |    5 +--
>  include/linux/irq.h     |   14 ++++-------
>  kernel/irq/manage.c     |   28 +++++++++++++++++++++-
>  kernel/irq/proc.c       |   57 ++++++++++++++++++++++++++++++++++++++++++++++-
>  4 files changed, 89 insertions(+), 15 deletions(-)
> 
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index 438a014..90f9ccc 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -16,6 +16,8 @@
>  
>  #ifdef CONFIG_SMP
>  
> +cpumask_t irq_default_affinity = CPU_MASK_ALL;
> +
>  /**
>   *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
>   *	@irq: interrupt number to wait for
> @@ -94,6 +96,27 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
>  	return 0;
>  }
>  
> +#ifndef CONFIG_AUTO_IRQ_AFFINITY
> +/**
> + * Generic version of the affinity autoselector.
> + */

Please don't use /** as the beginning of a comment block unless that
comment block is in kernel-doc format (this one is not).

> +int irq_select_affinity(unsigned int irq)
> +{
> +	cpumask_t mask;
> +
> +	if (!irq_can_set_affinity(irq))
> +		return 0;
> +
> +	cpus_and(mask, cpu_online_map, irq_default_affinity);
> +
> +	irq_desc[irq].affinity = mask;
> +	irq_desc[irq].chip->set_affinity(irq, mask);
> +
> +	set_balance_irq_affinity(irq, mask);
> +	return 0;
> +}
> +#endif


---
~Randy