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>
This commit is contained in:
Pavel Emelianov
2007-05-08 00:30:19 -07:00
committed by Linus Torvalds
parent db9c02fa8b
commit b5e618181a
9 changed files with 29 additions and 18 deletions

View File

@@ -453,7 +453,7 @@ void eventpoll_release_file(struct file *file)
mutex_lock(&epmutex);
while (!list_empty(lsthead)) {
epi = list_entry(lsthead->next, struct epitem, fllink);
epi = list_first_entry(lsthead, struct epitem, fllink);
ep = epi->ep;
list_del_init(&epi->fllink);
@@ -1143,7 +1143,7 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
if (nwait) {
while (!list_empty(lsthead)) {
pwq = list_entry(lsthead->next, struct eppoll_entry, llink);
pwq = list_first_entry(lsthead, struct eppoll_entry, llink);
list_del_init(&pwq->llink);
remove_wait_queue(pwq->whead, &pwq->wait);
@@ -1359,7 +1359,7 @@ static int ep_send_events(struct eventpoll *ep, struct list_head *txlist,
* read.
*/
for (eventcnt = 0; !list_empty(txlist) && eventcnt < maxevents;) {
epi = list_entry(txlist->next, struct epitem, rdllink);
epi = list_first_entry(txlist, struct epitem, rdllink);
prefetch(epi->rdllink.next);
/*