Re: [PATCH] X86: Change the default value of nr_irqs from 32 to NR_IRQs

Yinghai Lu
2008-08-19T17:44:53Z

On Tue, Aug 19, 2008 at 9:55 AM, Alex Nixon <alex.nixon@citrix.com> wrote:
> From: Alex Nixon <alex.nixon@citrix.com>
> Date: Tue, 19 Aug 2008 17:49:37 +0100
> Subject: [PATCH] X86: Change the default value of nr_irqs from 32 to NR_IRQs
>
> If the number of discovered IRQs is suspiciously low, this patch causes the number reported to default to NR_IRQS, rather than 32. NR_IRQS has already been defined to be a sensible value for the current system (in particular, at least 224 when paravirtualisation is involved).
>
> Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
> ---
> arch/x86/kernel/io_apic.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
> index 30ff794..11bffa1 100644
> --- a/arch/x86/kernel/io_apic.c
> +++ b/arch/x86/kernel/io_apic.c
> @@ -3632,7 +3632,7 @@ int __init probe_nr_irqs(void)
>
> /* something wrong ? */
> if (nr < 32)
> - nr = 32;
> + nr = NR_IRQS;
>
> return nr;
> }
> --
if only one ioapic, nr will be 24<<1, you will get 48. Does pv has io apic ?

YH