irq: only update affinity if ->set_affinity() is sucessfull
irq_set_affinity() and move_masked_irq() try to assign affinity
before calling chip set_affinity(). Some archs are assigning it
in ->set_affinity() again.
We do something like:
cpumask_cpy(desc->affinity, mask);
desc->chip->set_affinity(mask);
But in the failure path, affinity should not be touched - otherwise
we'll end up with a different affinity mask despite the failure to
migrate the IRQ.
So try to update the afffinity only if set_affinity returns with 0.
Also call irq_set_thread_affinity accordingly.
v2: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move"
v3: according to Ingo, change set_affinity() in irq_chip should return int.
v4: update comments by removing moving irq_desc code.
[ Impact: fix /proc/irq/*/smp_affinity setting corner case bug ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F65509.60307@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2734eca..aaf5c9d 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -80,7 +80,7 @@
return 1;
}
-static void
+void
irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
{
struct irqaction *action = desc->action;
@@ -109,17 +109,22 @@
spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
- if (desc->status & IRQ_MOVE_PCNTXT)
- desc->chip->set_affinity(irq, cpumask);
+ if (desc->status & IRQ_MOVE_PCNTXT) {
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc, cpumask);
+ }
+ }
else {
desc->status |= IRQ_MOVE_PENDING;
cpumask_copy(desc->pending_mask, cpumask);
}
#else
- cpumask_copy(desc->affinity, cpumask);
- desc->chip->set_affinity(irq, cpumask);
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc, cpumask);
+ }
#endif
- irq_set_thread_affinity(desc, cpumask);
desc->status |= IRQ_AFFINITY_SET;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
