lib: percpu_count_sum()

Provide an accurate version of percpu_counter_read.

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>

2 files changed, 20 insertions, 4 deletions

diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h
index dd89eb978393..21e054595bcb 100644
--- a/include/linux/percpu_counter.h
+++ b/include/linux/percpu_counter.h
@@ -34,13 +34,24 @@ void percpu_counter_init(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);
-s64 percpu_counter_sum_positive(struct percpu_counter *fbc);
+s64 __percpu_counter_sum(struct percpu_counter *fbc);
 
 static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)
 {
         __percpu_counter_add(fbc, amount, FBC_BATCH);
 }
 
+static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
+{
+        s64 ret = __percpu_counter_sum(fbc);
+        return ret < 0 ? 0 : ret;
+}
+
+static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
+{
+        return __percpu_counter_sum(fbc);
+}
+
 static inline s64 percpu_counter_read(struct percpu_counter *fbc)
 {
         return fbc->count;
@@ -107,6 +118,11 @@ static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
         return percpu_counter_read_positive(fbc);
 }
 
+static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
+{
+        return percpu_counter_read(fbc);
+}
+
 #endif  /* CONFIG_SMP */
 
 static inline void percpu_counter_inc(struct percpu_counter *fbc)
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index b0d80ea22a33..3b0ed80c1efd 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -52,7 +52,7 @@ EXPORT_SYMBOL(__percpu_counter_add);
  * Add up all the per-cpu counts, return the result.  This is a more accurate
  * but much slower version of percpu_counter_read_positive()
  */
-s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
+s64 __percpu_counter_sum(struct percpu_counter *fbc)
 {
         s64 ret;
         int cpu;
@@ -64,9 +64,9 @@ s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
                 ret += *pcount;
         }
         spin_unlock(&fbc->lock);
-        return ret < 0 ? 0 : ret;
+        return ret;
 }
-EXPORT_SYMBOL(percpu_counter_sum_positive);
+EXPORT_SYMBOL(__percpu_counter_sum);
 
 void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {