[PATCH] - irq vector assignment

From: Jack Steiner
Date: Thu Jun 24 2010 - 15:34:20 EST


Try to assign irqs to cpus on the correct node & fall back to global
assignment only if node-local fails. This reduces the chances of
using all of the interrupt vectors of a single cpu.

Signed-off-by: Jack Steiner <steiner@xxxxxxx>


---
arch/x86/kernel/apic/io_apic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/io_apic.c 2010-06-24 12:58:11.658933610 -0500
+++ linux/arch/x86/kernel/apic/io_apic.c 2010-06-24 13:56:26.734380290 -0500
@@ -3259,7 +3259,9 @@ unsigned int create_irq_nr(unsigned int
desc_new = move_irq_desc(desc_new, node);
cfg_new = desc_new->chip_data;

- if (__assign_irq_vector(new, cfg_new, apic->target_cpus()) == 0)
+ if (node >= 0 && __assign_irq_vector(new, cfg_new, node_to_cpumask_map[node]) == 0)
+ irq = new;
+ else if (__assign_irq_vector(new, cfg_new, apic->target_cpus()) == 0)
irq = new;
break;
}
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