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authorChangli Gao <xiaosuo@gmail.com>2010-05-07 14:33:26 +0800
committerIngo Molnar <mingo@elte.hu>2010-05-11 17:43:58 +0200
commita93d2f1744206827ccf416e2cdc5018aa503314e (patch)
treec4c9daf16536d8d58db275617e19898f6c5bdbd7
parentaf507ae8a0512a83728b17d8f8c5fa1561669f50 (diff)
downloadlinux-a93d2f1744206827ccf416e2cdc5018aa503314e.tar.bz2
sched, wait: Use wrapper functions
epoll should not touch flags in wait_queue_t. This patch introduces a new function __add_wait_queue_exclusive(), for the users, who use wait queue as a LIFO queue. __add_wait_queue_tail_exclusive() is introduced too instead of add_wait_queue_exclusive_locked(). remove_wait_queue_locked() is removed, as it is a duplicate of __remove_wait_queue(), disliked by users, and with less users. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: <containers@lists.linux-foundation.org> LKML-Reference: <1273214006-2979-1-git-send-email-xiaosuo@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--fs/eventpoll.c3
-rw-r--r--include/linux/wait.h35
-rw-r--r--kernel/cgroup.c2
-rw-r--r--kernel/sched.c3
4 files changed, 18 insertions, 25 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index bd056a5b4efc..3817149919cb 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1140,8 +1140,7 @@ retry:
* ep_poll_callback() when events will become available.
*/
init_waitqueue_entry(&wait, current);
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue(&ep->wq, &wait);
+ __add_wait_queue_exclusive(&ep->wq, &wait);
for (;;) {
/*
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a48e16b77d5e..76d96d035ea0 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -127,12 +127,26 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
/*
* Used for wake-one threads:
*/
+static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
+ wait_queue_t *wait)
+{
+ wait->flags |= WQ_FLAG_EXCLUSIVE;
+ __add_wait_queue(q, wait);
+}
+
static inline void __add_wait_queue_tail(wait_queue_head_t *head,
- wait_queue_t *new)
+ wait_queue_t *new)
{
list_add_tail(&new->task_list, &head->task_list);
}
+static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
+ wait_queue_t *wait)
+{
+ wait->flags |= WQ_FLAG_EXCLUSIVE;
+ __add_wait_queue_tail(q, wait);
+}
+
static inline void __remove_wait_queue(wait_queue_head_t *head,
wait_queue_t *old)
{
@@ -404,25 +418,6 @@ do { \
})
/*
- * Must be called with the spinlock in the wait_queue_head_t held.
- */
-static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
- wait_queue_t * wait)
-{
- wait->flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(q, wait);
-}
-
-/*
- * Must be called with the spinlock in the wait_queue_head_t held.
- */
-static inline void remove_wait_queue_locked(wait_queue_head_t *q,
- wait_queue_t * wait)
-{
- __remove_wait_queue(q, wait);
-}
-
-/*
* These are the old interfaces to sleep waiting for an event.
* They are racy. DO NOT use them, use the wait_event* interfaces above.
* We plan to remove these interfaces.
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e2769e13980c..4a07d057a265 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3010,7 +3010,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
unsigned long flags = (unsigned long)key;
if (flags & POLLHUP) {
- remove_wait_queue_locked(event->wqh, &event->wait);
+ __remove_wait_queue(event->wqh, &event->wait);
spin_lock(&cgrp->event_list_lock);
list_del(&event->list);
spin_unlock(&cgrp->event_list_lock);
diff --git a/kernel/sched.c b/kernel/sched.c
index 39aa9c7e22c0..b531d7934083 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3983,8 +3983,7 @@ do_wait_for_common(struct completion *x, long timeout, int state)
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
- wait.flags |= WQ_FLAG_EXCLUSIVE;
- __add_wait_queue_tail(&x->wait, &wait);
+ __add_wait_queue_tail_exclusive(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;