The patch titled
Add irq protection in the percpu-counters cpu-hotplug-callback path
has been added to the -mm tree. Its filename is
add-irq-protection-in-the-percpu-counters-cpu-hotplug-callback-path.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Add irq protection in the percpu-counters cpu-hotplug-callback path
From: Gautham R Shenoy <ego@xxxxxxxxxx>
Some of the per-cpu counters and thus their locks are accessed from IRQ
contexts. This can cause a deadlock if it interrupts a cpu-offline thread
which is transferring a dead-cpu's counts to the global counter.
Add appropriate IRQ protection in the cpu-hotplug callback path.
Signed-off-by: Gautham R Shenoy <ego@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/percpu_counter.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN lib/percpu_counter.c~add-irq-protection-in-the-percpu-counters-cpu-hotplug-callback-path lib/percpu_counter.c
--- a/lib/percpu_counter.c~add-irq-protection-in-the-percpu-counters-cpu-hotplug-callback-path
+++ a/lib/percpu_counter.c
@@ -124,12 +124,13 @@ static int __cpuinit percpu_counter_hotc
mutex_lock(&percpu_counters_lock);
list_for_each_entry(fbc, &percpu_counters, list) {
s32 *pcount;
+ unsigned long flags;
- spin_lock(&fbc->lock);
+ spin_lock_irqsave(&fbc->lock, flags);
pcount = per_cpu_ptr(fbc->counters, cpu);
fbc->count += *pcount;
*pcount = 0;
- spin_unlock(&fbc->lock);
+ spin_unlock_irqrestore(&fbc->lock, flags);
}
mutex_unlock(&percpu_counters_lock);
return NOTIFY_OK;
_
Patches currently in -mm which might be from ego@xxxxxxxxxx are
git-sched.patch
cpu-hotplug-slab-cleanup-cpuup_callback.patch
cpu-hotplug-slab-fix-memory-leak-in-cpu-hotplug-error-path.patch
cpu-hotplug-cpu-deliver-cpu_up_canceled-only-to-notify_oked-callbacks-with-cpu_up_prepare.patch
cpu-hotplug-topology-remove-topology_dev_map.patch
cpu-hotplug-thermal_throttle-fix-cpu-hotplug-error-handling.patch
cpu-hotplug-msr-fix-cpu-hotplug-error-handling.patch
cpu-hotplug-mce-fix-cpu-hotplug-error-handling.patch
cpu-hotplug-intel_cacheinfo-fix-cpu-hotplug-error-handling.patch
cpu-hotplug-intel_cacheinfo-fix-cpu-hotplug-error-handling-fix-a-section-mismatch-warning.patch
do-cpu_dead-migrating-under-read_locktasklist-instead-of-write_lock_irqtasklist.patch
do-cpu_dead-migrating-under-read_locktasklist-instead-of-write_lock_irqtasklist-fix.patch
migration_callcpu_dead-use-spin_lock_irq-instead-of-task_rq_lock.patch
add-irq-protection-in-the-percpu-counters-cpu-hotplug-callback-path.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
