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authorYinghai Lu <yinghai@kernel.org>2009-04-27 17:59:53 -0700
committerIngo Molnar <mingo@elte.hu>2009-04-28 12:21:16 +0200
commit57b150cce8e004ddd36330490a68bfb59b7271e9 (patch)
treef337b08b6cd9bbe165c709a7e5159b0d6d779238
parentd5dedd4507d307eb3f35f21b6e16f336fdc0d82a (diff)
downloadlwn-57b150cce8e004ddd36330490a68bfb59b7271e9.tar.gz
lwn-57b150cce8e004ddd36330490a68bfb59b7271e9.zip
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>
-rw-r--r--kernel/irq/internals.h3
-rw-r--r--kernel/irq/manage.c17
-rw-r--r--kernel/irq/migration.c14
3 files changed, 23 insertions, 11 deletions
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 01ce20eab38f..de5f412f6a92 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -42,6 +42,9 @@ static inline void unregister_handler_proc(unsigned int irq,
extern int irq_select_affinity_usr(unsigned int irq);
+extern void
+irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask);
+
/*
* Debugging printout:
*/
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2734eca59243..aaf5c9d05770 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -80,7 +80,7 @@ int irq_can_set_affinity(unsigned int irq)
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 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
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;
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index e05ad9be43b7..cfe767ca1545 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,5 +1,8 @@
#include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
void move_masked_irq(int irq)
{
@@ -39,11 +42,12 @@ void move_masked_irq(int irq)
* masking the irqs.
*/
if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
- < nr_cpu_ids)) {
- cpumask_and(desc->affinity,
- desc->pending_mask, cpu_online_mask);
- desc->chip->set_affinity(irq, desc->affinity);
- }
+ < nr_cpu_ids))
+ if (!desc->chip->set_affinity(irq, desc->pending_mask)) {
+ cpumask_copy(desc->affinity, desc->pending_mask);
+ irq_set_thread_affinity(desc, desc->pending_mask);
+ }
+
cpumask_clear(desc->pending_mask);
}