Re: [PATCH v3] x86/apic: limit irq affinity

[Yinghai Lu <yinghai@kernel.org>]

Dimitri Sivanich wrote:
> This patch allows for hard restrictions to irq affinity on x86 systems.
> 
> Affinity is masked to allow only those cpus which the subarchitecture
> deems accessible by the given irq.
> 
> On some UV systems, this domain will be limited to the nodes accessible
> to the irq's node.  Initially other X86 systems will not mask off any cpus
> so non-UV systems will remain unaffected.
> 
> Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
> 
> ---
> 
> Removed allowed cpumask from irq_cfg.  Storing allowed cpumasks in UV
> specific IRQ code.
> 
>  arch/x86/Kconfig                   |    1 
>  arch/x86/include/asm/hw_irq.h      |    3 
>  arch/x86/include/asm/uv/uv_irq.h   |    1 
>  arch/x86/include/asm/uv/uv_mmrs.h  |   25 ++++++
>  arch/x86/kernel/apic/io_apic.c     |  123 ++++++++++++++++++++++++++-------
>  arch/x86/kernel/apic/x2apic_uv_x.c |    4 -
>  arch/x86/kernel/uv_irq.c           |   58 +++++++++++++++
>  7 files changed, 189 insertions(+), 26 deletions(-)
> 
> Index: linux/arch/x86/kernel/apic/io_apic.c
> ===================================================================
> --- linux.orig/arch/x86/kernel/apic/io_apic.c	2009-10-19 15:22:52.000000000 -0500
> +++ linux/arch/x86/kernel/apic/io_apic.c	2009-10-19 20:57:29.000000000 -0500
> @@ -168,6 +168,17 @@ void __init io_apic_disable_legacy(void)
>  	nr_irqs_gsi = 0;
>  }
>  
> +static int default_irq_allowed_and(struct irq_cfg *cfg, struct cpumask *dstp,
> +						const struct cpumask *srcp)
> +{
> +	cpumask_copy(dstp, srcp);
> +
> +	return 1;
> +}
> +
> +int (*x86_irq_allowed_and)(struct irq_cfg *, struct cpumask *,
> +		const struct cpumask *) = default_irq_allowed_and;
> +
>  int __init arch_early_irq_init(void)
>  {
>  	struct irq_cfg *cfg;
> @@ -183,6 +194,7 @@ int __init arch_early_irq_init(void)
>  	for (i = 0; i < count; i++) {
>  		desc = irq_to_desc(i);
>  		desc->chip_data = &cfg[i];
> +		cfg->node = node;
>  		zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node);
>  		zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node);
>  		if (i < nr_legacy_irqs)
> @@ -231,12 +243,13 @@ int arch_init_chip_data(struct irq_desc 
>  
>  	cfg = desc->chip_data;
>  	if (!cfg) {
> -		desc->chip_data = get_one_free_irq_cfg(node);
> +		cfg = desc->chip_data = get_one_free_irq_cfg(node);
>  		if (!desc->chip_data) {
>  			printk(KERN_ERR "can not alloc irq_cfg\n");
>  			BUG_ON(1);
>  		}
>  	}
> +	cfg->node = node;

how about desc->node ?

YH