On Mon, 3 June 2013 13:28:03 -0400, Joern Engel wrote:
>
> Drawback is that object size is growing. I think an ideal compiler
> should be able to optimize all the overhead away, but 4.7 just isn't
> there yet. Or maybe I just messed up - patches are only
> compile-tested after all. Comments/ideas are welcome.
Actually, replacing the inline function with a bit of macro hell seems
to yield identical object size again. And in the case of
compression.o, it even removes 528 bytes or so of object code.
New 1/2 below.
Jörn
--
A defeated army first battles and then seeks victory.
-- Sun Tzu
[PATCH 1/2] list: add list_for_each_entry_del
I have seen a lot of boilerplate code that either follows the pattern of
while (!list_empty(head)) {
pos = list_entry(head->next, struct foo, list);
list_del(pos->list);
...
}
or some variant thereof.
With this patch in, people can use
list_for_each_entry_del(pos, head, list) {
...
}
The patch also adds a list_for_each_del variant, even though I have
only found a single user for that one so far.
Signed-off-by: Joern Engel <jo...@logfs.org>
---
include/linux/list.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/include/linux/list.h b/include/linux/list.h
index 6a1f8df..49325ca 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -483,6 +483,27 @@ static inline void list_splice_tail_init(struct list_head
*list,
pos = list_entry(pos->member.next, typeof(*pos), member))
/**
+ * list_for_each_remove - iterate over a list, deleting each entry
+ * @pos: the &struct list_head to use as a loop cursor.
+ * @head: the head of your list.
+ *
+ * Calls list_del() on pos on each iteration
+ */
+#define list_for_each_del(pos, head) \
+ while (list_empty(head) ? 0 : (pos = (head)->next, list_del(pos), 1))
+
+/**
+ * list_for_each_entry_remove - iterate over a list of given type, deleting
each entry
+ * @pos: the type * to use as loop cursor.
+ * @head: the head of your list.
+ * @member: the name of the list_struct within the struct
+ *
+ * Calls list_del() on pos on each iteration
+ */
+#define list_for_each_entry_del(pos, head, member) \
+ while (list_empty(head) ? 0 : (pos = list_first_entry((head),
typeof(*pos), member), list_del(&pos->member), 1))
+
+/**
* list_for_each_entry_safe - iterate over list of given type safe against
removal of list entry
* @pos: the type * to use as a loop cursor.
* @n: another type * to use as temporary storage
--
1.7.10.4
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