On Mon, 11 Feb 2008 11:47:17 +0300
"Denis V. Lunev" <[EMAIL PROTECTED]> wrote:
> net/ipv4/fib_trie.c: In function 'node_set_parent':
> net/ipv4/fib_trie.c:184: warning: assignment makes integer from pointer
> without a cast
>
> Signed-off-by: Denis V. Lunev <[EMAIL PROTECTED]>
> ---
> net/ipv4/fib_trie.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
> index f5fba3f..1753cd4 100644
> --- a/net/ipv4/fib_trie.c
> +++ b/net/ipv4/fib_trie.c
> @@ -177,10 +177,11 @@ static inline struct tnode *node_parent_rcu(struct node
> *node)
> return rcu_dereference(ret);
> }
>
> -static inline void node_set_parent(struct node *node, struct tnode *ptr)
> +static inline void node_set_parent(struct node *node, struct tnode *__ptr)
> {
> - rcu_assign_pointer(node->parent,
> - (unsigned long)ptr | NODE_TYPE(node));
> + struct node *ptr;
> + ptr = (struct node *)((unsigned long)__ptr | NODE_TYPE(node));
> + rcu_assign_pointer(node->parent, ptr);
> }
>
> static inline struct node *tnode_get_child(struct tnode *tn, unsigned int i)
No, this causes new warning from assigning pointer (ptr) to integer
node->parent.
Why not just change rcupdate.h to do the right thing.
>From a00f7cbf1c2f2282eced236e1e8b99b0fecd213a Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <[EMAIL PROTECTED]>
Date: Mon, 11 Feb 2008 11:28:13 -0800
Subject: [PATCH] eliminate warnings when rcu_assign_pointer is used with
unsigned long
It is reasonable to use RCU with non-pointer values, and describe
the optimization.
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
--
Stephen Hemminger <[EMAIL PROTECTED]>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
