[PATCH] Use NUMA node cpu mask in irq affinity

From: Prarit Bhargava
Date: Wed Feb 08 2012 - 15:48:34 EST


The irq affinity files (/proc/irq/.../smp_affinity) contain a mask that is used
to "pin" an irq to a set of cpus. On boot this set is currently all cpus.
This can be incorrect as ACPI SRAT may tell us that a specific device or
bus is attached to a particular node and it's cpus.

When setting up the irq affinity we should take into account the NUMA node
cpu mask by and'ing it into the irq's affinity mask.

Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
---
kernel/irq/manage.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index a9a9dbe..2fb3469 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -301,6 +301,8 @@ setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
}

cpumask_and(mask, cpu_online_mask, set);
+ if (desc->irq_data.node != -1)
+ cpumask_and(mask, mask, cpumask_of_node(desc->irq_data.node));
ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
switch (ret) {
case IRQ_SET_MASK_OK:
--
1.7.1

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