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Subject[PATCH] list_for_each_entry
Date
Using two variables all the time is pissing me off:

struct list_head *i;
list_for_each(i, &head) {
struct foo *f = list_entry(i, struct foo, list);
...
}

Much nicer is:
struct foo *f;
list_for_each_entry(f, &head, list) {
...
}

Asm code produced is identical.

Cheers,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: list_for_each_entry patch
Author: Rusty Russell
Status: Trivial

D: This adds list_for_each_entry, which is the equivalent of
D: list_for_each and list_entry, except only one variable is needed.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.4.19/include/linux/list.h working-2.4.19-conntrack-fast/include/linux/list.h
--- linux-2.4.19/include/linux/list.h 2002-08-21 18:14:34.000000000 +1000
+++ working-2.4.19-conntrack-fast/include/linux/list.h 2002-08-21 19:35:09.000000000 +1000
@@ -171,6 +171,18 @@ static __inline__ void list_splice(struc
for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
pos = pos->prev, prefetch(pos->prev))

+/**
+ * list_for_each_entry - iterate over list of given type
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ prefetch(pos->member.next); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member), \
+ prefetch(pos->member.next))

#endif /* __KERNEL__ || _LVM_H_INCLUDE */

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