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

From: Yinghai Lu
Date: Tue Oct 20 2009 - 14:59:37 EST


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@xxxxxxx>
>
> ---
>
> 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
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