Re: [PATCH] asm-generic: Raise default NR_IRQS when using sparseIRQs

From: Thomas Gleixner
Date: Thu Jun 30 2011 - 03:27:30 EST


On Wed, 29 Jun 2011, Mark Brown wrote:

> Rather than have each platform using sparse IRQs pick a suitably large
> NR_IRQS for use with sparse IRQs make the default high when they are
> enabled. We pick 64k as there is still a bitmap of IRQs that is
> allocated statically, and as we all know 64k should be enough for
> anyone.

The sparse bitmap is overallocated to NR_IRQS + 8k anyway, so that's
rather pointless.

> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> include/asm-generic/irq.h | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/include/asm-generic/irq.h b/include/asm-generic/irq.h
> index b90ec0b..0d95650 100644
> --- a/include/asm-generic/irq.h
> +++ b/include/asm-generic/irq.h
> @@ -4,11 +4,15 @@
> /*
> * NR_IRQS is the upper bound of how many interrupts can be handled
> * in the platform. It is used to size the static irq_map array,
> - * so don't make it too big.
> + * so don't make it too big unless we're using sparse IRQs.
> */
> #ifndef NR_IRQS
> +#ifdef CONFIG_SPARSE_IRQ
> +#define NR_IRQS 0xffff
> +#else
> #define NR_IRQS 64
> #endif
> +#endif
>
> static inline int irq_canonicalize(int irq)
> {
> --
> 1.7.5.4
>
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