Eliminate warnings when rcu_assign_pointer is used with unsigned long.
It is reasonable to use RCU with non-pointer values so allow it for general
use. Add a comment to explain the if test.
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
---
include/linux/rcupdate.h | 13 +++++++------
1 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 37a642c..c44ac87 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -172,14 +172,15 @@ struct rcu_head {
* structure after the pointer assignment. More importantly, this
* call documents which pointers will be dereferenced by RCU read-side
* code.
+ *
+ * If value is the NULL (constant 0), then no barrier is needed.
*/
-#define rcu_assign_pointer(p, v) \
- ({ \
- if (!__builtin_constant_p(v) || \
- ((v) != NULL)) \
- smp_wmb(); \
- (p) = (v); \
+#define rcu_assign_pointer(p, v) \
+ ({ \
+ if (!(__builtin_constant_p(v) && v)) \
+ smp_wmb(); \
+ (p) = (v); \
})
/**
--
1.5.3.8
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