2008-02-19 11:52:42

by Franck Bui-Huu

Subject: [PATCH 2/2] rculist.h: use the rcu API

From: Franck Bui-Huu <[email protected]>

This patch makes almost all list mutation primitives use
rcu_assign_pointer().

The main point of this being readability improvement.

Signed-off-by: Franck Bui-Huu <[email protected]>
---
include/linux/rculist.h | 23 +++++++++--------------
1 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index aa9b3eb..8d2c81f 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -7,6 +7,7 @@
* RCU-protected list version
*/
#include <linux/list.h>
+#include <linux/rcupdate.h>

/*
* Insert a new entry between two known consecutive entries.
@@ -19,9 +20,8 @@ static inline void __list_add_rcu(struct list_head *new,
{
new->next = next;
new->prev = prev;
- smp_wmb();
+ rcu_assign_pointer(prev->next, new);
next->prev = new;
- prev->next = new;
}

/**
@@ -110,9 +110,8 @@ static inline void list_replace_rcu(struct list_head *old,
{
new->next = old->next;
new->prev = old->prev;
- smp_wmb();
+ rcu_assign_pointer(new->prev->next, new);
new->next->prev = new;
- new->prev->next = new;
old->prev = LIST_POISON2;
}

@@ -166,8 +165,7 @@ static inline void list_splice_init_rcu(struct list_head *list,
*/

last->next = at;
- smp_wmb();
- head->next = first;
+ rcu_assign_pointer(head->next, first);
first->prev = head;
at->prev = last;
}
@@ -280,10 +278,9 @@ static inline void hlist_replace_rcu(struct hlist_node *old,

new->next = next;
new->pprev = old->pprev;
- smp_wmb();
+ rcu_assign_pointer(*new->pprev, new);
if (next)
new->next->pprev = &new->next;
- *new->pprev = new;
old->pprev = LIST_POISON2;
}

@@ -310,12 +307,12 @@ static inline void hlist_add_head_rcu(struct hlist_node *n,
struct hlist_head *h)
{
struct hlist_node *first = h->first;
+
n->next = first;
n->pprev = &h->first;
- smp_wmb();
+ rcu_assign_pointer(h->first, n);
if (first)
first->pprev = &n->next;
- h->first = n;
}

/**
@@ -341,9 +338,8 @@ static inline void hlist_add_before_rcu(struct hlist_node *n,
{
n->pprev = next->pprev;
n->next = next;
- smp_wmb();
+ rcu_assign_pointer(*(n->pprev), n);
next->pprev = &n->next;
- *(n->pprev) = n;
}

/**
@@ -369,8 +365,7 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev,
{
n->next = prev->next;
n->pprev = &prev->next;
- smp_wmb();
- prev->next = n;
+ rcu_assign_pointer(prev->next, n);
if (n->next)
n->next->pprev = &n->next;
}
--
1.5.4