lib: percpu_counter_init_irq
provide a way to tell lockdep about percpu_counters that are supposed to be
used from irq safe contexts.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h
index f7ecd38..9007ccd 100644
--- a/include/linux/percpu_counter.h
+++ b/include/linux/percpu_counter.h
@@ -31,6 +31,7 @@
#endif
int percpu_counter_init(struct percpu_counter *fbc, s64 amount);
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount);
void percpu_counter_destroy(struct percpu_counter *fbc);
void percpu_counter_set(struct percpu_counter *fbc, s64 amount);
void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch);
@@ -84,6 +85,8 @@
return 0;
}
+#define percpu_counter_init_irq percpu_counter_init
+
static inline void percpu_counter_destroy(struct percpu_counter *fbc)
{
}
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 3a59d84..9659eab 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -68,6 +68,8 @@
}
EXPORT_SYMBOL(__percpu_counter_sum);
+static struct lock_class_key percpu_counter_irqsafe;
+
int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
{
spin_lock_init(&fbc->lock);
@@ -84,6 +86,16 @@
}
EXPORT_SYMBOL(percpu_counter_init);
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount)
+{
+ int err;
+
+ err = percpu_counter_init(fbc, amount);
+ if (!err)
+ lockdep_set_class(&fbc->lock, &percpu_counter_irqsafe);
+ return err;
+}
+
void percpu_counter_destroy(struct percpu_counter *fbc)
{
if (!fbc->counters)