Re: [RFC/PATCH] notify user-level IRQ balancer when kernel assigns IRQ affinity

[David Daney <ddaney@caviumnetworks.com>]

On 09/03/2010 02:05 PM, Arthur Kepner wrote:
>
> We've run into situations where a CPU runs out of interrupt
> vectors, because all the interrupts are getting the default
> affinity (and the interrupt balancer hasn't yet run).
>
> The following emits a netlink message whenever an interrupt
> is given a default CPU affinity. A user-level IRQ balancer
> can use those messages to decide if, and how to reassign
> affinities. This should allow us to avoid running out of
> vectors on any particular CPU (or at least make it far less
> likely).
>
> I know this needs work, but would like to get comments on
> the idea before doing more coding and testing.
>
>
> Signed-off-by: Arthur Kepner<akepner@sgi.com>
>
> ---
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 4877a8c..65c79c7 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -158,4 +158,15 @@ config HAVE_PERF_EVENTS_NMI
>   	  subsystem.  Also has support for calculating CPU cycle events
>   	  to determine how many clock cycles in a given period.
>
> +config NOTIFY_USER_IRQ_BALANCER
> +	bool "Notify user-level IRQ balancer (EXPERIMENTAL)"
> +	default n
> +	depends on NET&&  X86

Missing a space before that '&&', but more importantly, what part of the 
patch is x86 specific?


David Daney