[PATCH 06/17] lib: percpu_counter_init_irq

From: Peter Zijlstra
Date: Thu Jun 14 2007 - 18:10:05 EST


provide a way to init percpu_counters that are supposed to be used from irq
safe contexts.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
include/linux/percpu_counter.h | 4 ++++
lib/percpu_counter.c | 8 ++++++++
2 files changed, 12 insertions(+)

Index: linux-2.6/include/linux/percpu_counter.h
===================================================================
--- linux-2.6.orig/include/linux/percpu_counter.h
+++ linux-2.6/include/linux/percpu_counter.h
@@ -31,6 +31,8 @@ struct percpu_counter {
#endif

void percpu_counter_init(struct percpu_counter *fbc, s64 amount);
+void 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_mod(struct percpu_counter *fbc, s32 amount, s32 batch);
@@ -89,6 +91,8 @@ static inline void percpu_counter_init(s
fbc->count = amount;
}

+#define percpu_counter_init_irq percpu_counter_init
+
static inline void percpu_counter_destroy(struct percpu_counter *fbc)
{
}
Index: linux-2.6/lib/percpu_counter.c
===================================================================
--- linux-2.6.orig/lib/percpu_counter.c
+++ linux-2.6/lib/percpu_counter.c
@@ -87,6 +87,8 @@ s64 __percpu_counter_sum(struct percpu_c
}
EXPORT_SYMBOL(__percpu_counter_sum);

+static struct lock_class_key percpu_counter_irqsafe;
+
void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
{
spin_lock_init(&fbc->lock);
@@ -100,6 +102,12 @@ void percpu_counter_init(struct percpu_c
}
EXPORT_SYMBOL(percpu_counter_init);

+void percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount)
+{
+ percpu_counter_init(fbc, amount);
+ lockdep_set_class(&fbc->lock, &percpu_counter_irqsafe);
+}
+
void percpu_counter_destroy(struct percpu_counter *fbc)
{
free_percpu(fbc->counters);

--

-
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