* [PATCH] [IPV4]: Remove warning in node_set_parent. @ 2008-02-11 8:47 Denis V. Lunev 2008-02-11 19:48 ` Stephen Hemminger 0 siblings, 1 reply; 3+ messages in thread From: Denis V. Lunev @ 2008-02-11 8:47 UTC (permalink / raw) To: davem; +Cc: netdev, devel, shemminger, Denis V. Lunev 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 <den@openvz.org> --- 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) -- 1.5.3.rc5 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] [IPV4]: Remove warning in node_set_parent. 2008-02-11 8:47 [PATCH] [IPV4]: Remove warning in node_set_parent Denis V. Lunev @ 2008-02-11 19:48 ` Stephen Hemminger 2008-02-12 8:11 ` Denis V. Lunev 0 siblings, 1 reply; 3+ messages in thread From: Stephen Hemminger @ 2008-02-11 19:48 UTC (permalink / raw) To: Denis V. Lunev; +Cc: davem, netdev, devel, Denis V. Lunev On Mon, 11 Feb 2008 11:47:17 +0300 "Denis V. Lunev" <den@openvz.org> 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 <den@openvz.org> > --- > 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 <stephen.hemminger@vyatta.com> 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 <shemminger@vyatta.com> --- 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 <stephen.hemminger@vyatta.com> ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] [IPV4]: Remove warning in node_set_parent. 2008-02-11 19:48 ` Stephen Hemminger @ 2008-02-12 8:11 ` Denis V. Lunev 0 siblings, 0 replies; 3+ messages in thread From: Denis V. Lunev @ 2008-02-12 8:11 UTC (permalink / raw) To: Stephen Hemminger; +Cc: davem, netdev, devel ugly :), but Acked-by: Denis V. Lunev <den@openvz.org> On Mon, 2008-02-11 at 11:48 -0800, Stephen Hemminger wrote: > On Mon, 11 Feb 2008 11:47:17 +0300 > "Denis V. Lunev" <den@openvz.org> 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 <den@openvz.org> > > --- > > 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 <stephen.hemminger@vyatta.com> > 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 <shemminger@vyatta.com> > --- > 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 > > > > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2008-02-12 8:11 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2008-02-11 8:47 [PATCH] [IPV4]: Remove warning in node_set_parent Denis V. Lunev 2008-02-11 19:48 ` Stephen Hemminger 2008-02-12 8:11 ` Denis V. Lunev
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