[patch v3 1/3] percpu_counter: change return value and add comments

[shaohua.li@intel.com]

[-- Attachment #1: percpu-counter-positive.patch --]
[-- Type: text/plain, Size: 1164 bytes --]

the percpu_counter_*_positive() API in UP case doesn't check if return value is
positive. Add comments to explain why we don't.
Also if count < 0, returns 0 instead of 1 for *read_positive().

Signed-off-by: Shaohua Li <shaohua.li@intel.com>

---
 include/linux/percpu_counter.h |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Index: linux/include/linux/percpu_counter.h
===================================================================
--- linux.orig/include/linux/percpu_counter.h	2011-04-13 16:09:22.000000000 +0800
+++ linux/include/linux/percpu_counter.h	2011-04-14 08:50:45.000000000 +0800
@@ -75,7 +75,7 @@ static inline s64 percpu_counter_read_po
 	barrier();		/* Prevent reloads of fbc->count */
 	if (ret >= 0)
 		return ret;
-	return 1;
+	return 0;
 }
 
 static inline int percpu_counter_initialized(struct percpu_counter *fbc)
@@ -133,6 +133,10 @@ static inline s64 percpu_counter_read(st
 	return fbc->count;
 }
 
+/*
+ * percpu_counter is intended to track positive number. In UP case, the number
+ * should never be negative.
+ */
 static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
 {
 	return fbc->count;