This is a note to let you know that I've just added the patch titled
arm64: use cpu_online_mask when using forced irq_set_affinity
to the 3.14-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:
arm64-use-cpu_online_mask-when-using-forced-irq_set_affinity.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 601c942176d8ad8334118bddb747e3720bed24f8 Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@xxxxxxx>
Date: Fri, 9 May 2014 17:37:44 +0100
Subject: arm64: use cpu_online_mask when using forced irq_set_affinity
From: Sudeep Holla <sudeep.holla@xxxxxxx>
commit 601c942176d8ad8334118bddb747e3720bed24f8 upstream.
Commit 01f8fa4f01d8("genirq: Allow forcing cpu affinity of interrupts")
enabled the forced irq_set_affinity which previously refused to route an
interrupt to an offline cpu.
Commit ffde1de64012("irqchip: Gic: Support forced affinity setting")
implements this force logic and disables the cpu online check for GIC
interrupt controller.
When __cpu_disable calls migrate_irqs, it disables the current cpu in
cpu_online_mask and uses forced irq_set_affinity to migrate the IRQs
away from the cpu but passes affinity mask with the cpu being offlined
also included in it.
When calling irq_set_affinity with force == true in a cpu hotplug path,
the caller must ensure that the cpu being offlined is not present in the
affinity mask or it may be selected as the target CPU, leading to the
interrupt not being migrated.
This patch uses cpu_online_mask when using forced irq_set_affinity so
that the IRQs are properly migrated away.
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/irq.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -97,11 +97,15 @@ static bool migrate_one_irq(struct irq_d
if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
return false;
- if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
- affinity = cpu_online_mask;
+ if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids)
ret = true;
- }
+ /*
+ * when using forced irq_set_affinity we must ensure that the cpu
+ * being offlined is not present in the affinity mask, it may be
+ * selected as the target CPU otherwise
+ */
+ affinity = cpu_online_mask;
c = irq_data_get_irq_chip(d);
if (!c->irq_set_affinity)
pr_debug("IRQ%u: unable to set affinity\n", d->irq);
Patches currently in stable-queue which might be from sudeep.holla@xxxxxxx are
queue-3.14/arm64-use-cpu_online_mask-when-using-forced-irq_set_affinity.patch
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