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author | Pavel Emelianov <xemul@sw.ru> | 2007-05-08 00:30:19 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:11 -0700 |
commit | b5e618181a927210f8be1d3d2249d31904ba358d (patch) | |
tree | 731f1ae4ff1ba56d402bb329182b7d935bb439a1 /include/linux/list.h | |
parent | db9c02fa8bd50eb104781a9f78cae923d8da1e74 (diff) | |
download | linux-3.10-b5e618181a927210f8be1d3d2249d31904ba358d.tar.gz linux-3.10-b5e618181a927210f8be1d3d2249d31904ba358d.tar.bz2 linux-3.10-b5e618181a927210f8be1d3d2249d31904ba358d.zip |
Introduce a handy list_first_entry macro
There are many places in the kernel where the construction like
foo = list_entry(head->next, struct foo_struct, list);
are used.
The code might look more descriptive and neat if using the macro
list_first_entry(head, type, member) \
list_entry((head)->next, type, member)
Here is the macro itself and the examples of its usage in the generic code.
If it will turn out to be useful, I can prepare the set of patches to
inject in into arch-specific code, drivers, networking, etc.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/list.h')
-rw-r--r-- | include/linux/list.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index f9d71eab05e..9202703be2a 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -426,6 +426,17 @@ static inline void list_splice_init_rcu(struct list_head *list, container_of(ptr, type, member) /** + * list_first_entry - get the first element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/** * list_for_each - iterate over a list * @pos: the &struct list_head to use as a loop cursor. * @head: the head for your list. |