[patch/revised] wake_up_info() ...
From: Davide Libenzi
Date: Mon Jan 05 2004 - 13:57:19 EST
Since Manfred and Linus preferred a simpler approach, now the info is
passed only to the wake up callback, w/out any storage. This works right
away for callback'd driven wake ups like, for example, epoll. A task that
wants a std wake up *and* wants to fetch wake up info, needs to initialize
the wait structure with its own callback function, copy the info during
the callback call, and wake itself up from inside the callback.
Comments?
- Davide
--- linux-2.5/fs/eventpoll.c._orig 2004-01-05 10:43:55.079273352 -0800
+++ linux-2.5/fs/eventpoll.c 2004-01-05 10:44:39.027592192 -0800
@@ -306,7 +306,8 @@
static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi);
static int ep_unlink(struct eventpoll *ep, struct epitem *epi);
static int ep_remove(struct eventpoll *ep, struct epitem *epi);
-static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync);
+static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info);
static int ep_eventpoll_close(struct inode *inode, struct file *file);
static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait);
static int ep_collect_ready_items(struct eventpoll *ep,
@@ -1293,7 +1294,8 @@
* machanism. It is called by the stored file descriptors when they
* have events to report.
*/
-static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync)
+static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info)
{
int pwake = 0;
unsigned long flags;
--- linux-2.5/include/linux/wait.h._orig 2004-01-05 09:22:33.802340240 -0800
+++ linux-2.5/include/linux/wait.h 2004-01-05 10:35:00.030613112 -0800
@@ -17,8 +17,10 @@
#include <asm/system.h>
typedef struct __wait_queue wait_queue_t;
-typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync);
-extern int default_wake_function(wait_queue_t *wait, unsigned mode, int sync);
+typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info);
+extern int default_wake_function(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info);
struct __wait_queue {
unsigned int flags;
@@ -107,6 +109,7 @@
extern void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr));
extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
+extern void FASTCALL(__wake_up_info(wait_queue_head_t *q, unsigned int mode, int nr, unsigned long info));
#define wake_up(x) __wake_up((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1)
#define wake_up_nr(x, nr) __wake_up((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr)
@@ -117,6 +120,8 @@
#define wake_up_interruptible_all(x) __wake_up((x),TASK_INTERRUPTIBLE, 0)
#define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
+#define wake_up_info(x, i) __wake_up_info((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, (i))
+#define wake_up_all_info(x, i) __wake_up_info((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, (i))
#define __wait_event(wq, condition) \
do { \
@@ -240,7 +245,8 @@
void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
wait_queue_t *wait, int state));
void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
-int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync);
+int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info);
#define DEFINE_WAIT(name) \
wait_queue_t name = { \
--- linux-2.5/kernel/sched.c._orig 2004-01-05 09:22:34.609217576 -0800
+++ linux-2.5/kernel/sched.c 2004-01-05 10:26:56.606104808 -0800
@@ -1632,7 +1632,8 @@
EXPORT_SYMBOL(preempt_schedule);
#endif /* CONFIG_PREEMPT */
-int default_wake_function(wait_queue_t *curr, unsigned mode, int sync)
+int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
+ unsigned long info)
{
task_t *p = curr->task;
return try_to_wake_up(p, mode, sync);
@@ -1649,7 +1650,8 @@
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
-static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, int sync)
+static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
+ int nr_exclusive, int sync, unsigned long info)
{
struct list_head *tmp, *next;
@@ -1658,7 +1660,7 @@
unsigned flags;
curr = list_entry(tmp, wait_queue_t, task_list);
flags = curr->flags;
- if (curr->func(curr, mode, sync) &&
+ if (curr->func(curr, mode, sync, info) &&
(flags & WQ_FLAG_EXCLUSIVE) &&
!--nr_exclusive)
break;
@@ -1676,7 +1678,7 @@
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, 0);
+ __wake_up_common(q, mode, nr_exclusive, 0, 0);
spin_unlock_irqrestore(&q->lock, flags);
}
@@ -1687,7 +1689,7 @@
*/
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
{
- __wake_up_common(q, mode, 1, 0);
+ __wake_up_common(q, mode, 1, 0, 0);
}
/**
@@ -1712,21 +1714,41 @@
spin_lock_irqsave(&q->lock, flags);
if (likely(nr_exclusive))
- __wake_up_common(q, mode, nr_exclusive, 1);
+ __wake_up_common(q, mode, nr_exclusive, 1, 0);
else
- __wake_up_common(q, mode, nr_exclusive, 0);
+ __wake_up_common(q, mode, nr_exclusive, 0, 0);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
+/**
+ * __wake_up_info - wake up threads blocked on a waitqueue by passing an information token.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @info: information token passed to waiters
+ */
+void __wake_up_info(wait_queue_head_t *q, unsigned int mode, int nr_exclusive,
+ unsigned long info)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __wake_up_common(q, mode, nr_exclusive, 0, info);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+
+EXPORT_SYMBOL(__wake_up_info);
+
void complete(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, 0);
+ __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
+ 1, 0, 0);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
@@ -1738,7 +1760,8 @@
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, 0);
+ __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
+ 0, 0, 0);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
--- linux-2.5/kernel/fork.c._orig 2004-01-05 10:27:49.078127848 -0800
+++ linux-2.5/kernel/fork.c 2004-01-05 10:36:11.912685376 -0800
@@ -194,9 +194,10 @@
EXPORT_SYMBOL(finish_wait);
-int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync)
+int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync,
+ unsigned long info)
{
- int ret = default_wake_function(wait, mode, sync);
+ int ret = default_wake_function(wait, mode, sync, info);
if (ret)
list_del_init(&wait->task_list);
-
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