This is a note to let you know that I've just added the patch titled
ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs
to the 3.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-7406-1-hotplug-copy-the-affinity-mask-when-forcefully-migrating-irqs.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 Mon Sep 17 00:00:00 2001
From: Will Deacon <[email protected]>
Date: Fri, 27 Apr 2012 12:56:24 +0100
Subject: ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating
IRQs
From: Will Deacon <[email protected]>
commit 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 upstream.
When a CPU is hotplugged off, we migrate any IRQs currently affine to it
away and onto another online CPU by calling the irq_set_affinity
function of the relevant interrupt controller chip. This function
returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate
whether irq_data.affinity was updated.
If we are forcefully migrating an interrupt (because the affinity mask
no longer identifies any online CPUs) then we should update the IRQ
affinity mask to reflect the new CPU set. Failure to do so can
potentially leave /proc/irq/n/smp_affinity identifying only offline
CPUs, which may confuse userspace IRQ balancing daemons.
This patch updates migrate_one_irq to copy the affinity mask when
the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the
affinity of an interrupt.
Reported-by: Leif Lindholm <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Russell King <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/arm/kernel/irq.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -156,10 +156,10 @@ static bool migrate_one_irq(struct irq_d
}
c = irq_data_get_irq_chip(d);
- if (c->irq_set_affinity)
- c->irq_set_affinity(d, affinity, true);
- else
+ if (!c->irq_set_affinity)
pr_debug("IRQ%u: unable to set affinity\n", d->irq);
+ else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK &&
ret)
+ cpumask_copy(d->affinity, affinity);
return ret;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.3/arm-7396-1-errata-only-handle-arm-erratum-326103-on-affected-cores.patch
queue-3.3/arm-7403-1-tls-remove-covert-channel-via-tpidrurw.patch
queue-3.3/arm-7406-1-hotplug-copy-the-affinity-mask-when-forcefully-migrating-irqs.patch
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