Re: [tip:x86/irq] x86: apic: Fix mismerge, add arch_probe_nr_irqs() again

[Yinghai Lu <yinghai@kernel.org>]

On 02/26/2010 02:26 AM, tip-bot for Ingo Molnar wrote:
> Commit-ID:  f6a929eb62ef43cae16ba6d4e2c64b4e430fe7a4
> Gitweb:     http://git.kernel.org/tip/f6a929eb62ef43cae16ba6d4e2c64b4e430fe7a4
> Author:     Ingo Molnar <mingo@elte.hu>
> AuthorDate: Fri, 26 Feb 2010 11:17:16 +0100
> Committer:  Ingo Molnar <mingo@elte.hu>
> CommitDate: Fri, 26 Feb 2010 11:17:16 +0100
> 
> x86: apic: Fix mismerge, add arch_probe_nr_irqs() again
> 
> Merge commit aef55d4922 mis-merged io_apic.c so we lost the
> arch_probe_nr_irqs() method.
> 
> This caused subtle boot breakages (udev confusion likely
> due to missing drivers) with certain configs.
> 
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Yinghai Lu <yinghai@kernel.org>
> LKML-Reference: <20100207210250.GB8256@jenkins.home.ifup.org>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> ---
>  arch/x86/kernel/apic/io_apic.c |   22 ++++++++++++++++++++++
>  1 files changed, 22 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index 527390c..c13ab8f 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -3874,6 +3874,28 @@ void __init probe_nr_irqs_gsi(void)
>  	printk(KERN_DEBUG "nr_irqs_gsi: %d\n", nr_irqs_gsi);
>  }
>  
> +#ifdef CONFIG_SPARSE_IRQ
> +int __init arch_probe_nr_irqs(void)
> +{
> +	int nr;
> +
> +	if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
> +		nr_irqs = NR_VECTORS * nr_cpu_ids;
> +
> +	nr = nr_irqs_gsi + 8 * nr_cpu_ids;
> +#if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
> +	/*
> +	 * for MSI and HT dyn irq
> +	 */
> +	nr += nr_irqs_gsi * 16;
> +#endif
> +	if (nr < nr_irqs)
> +		nr_irqs = nr;
> +
> +	return 0;
> +}
> +#endif
> +
>  static int __io_apic_set_pci_routing(struct device *dev, int irq,
>  				struct io_apic_irq_attr *irq_attr)
>  {

for x86, with radix tree based irq_to_desc(),
removing arch_probe_nr_irqs is intentional. so we get more irq that could be used.

wonder if the udev for some of your test system have irq number limitation?

YH