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authorLinus Torvalds <torvalds@linux-foundation.org>2009-02-08 12:35:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-08 12:35:26 -0800
commit58edf8ee5e3319373dae9d9038e1a8469a83bb76 (patch)
tree68d03381fb822e6a931b0113b27c4cf133c6eb4e
parent1fb25cb8b83e85f5bf1a4adb3c9a254c4ce92405 (diff)
parentf7de7621f07495ad14fb23a812003bcf8f6af65a (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-update
* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async-update: async: use list_move_tail async: Rename _special -> _domain for clarity. async: Add some documentation. async: Handle kthread_run() return codes. async: Fix running list handling.
-rw-r--r--fs/super.c4
-rw-r--r--include/linux/async.h8
-rw-r--r--kernel/async.c82
3 files changed, 76 insertions, 18 deletions
diff --git a/fs/super.c b/fs/super.c
index 645e5403f2a0..61dce001dd57 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -301,7 +301,7 @@ void generic_shutdown_super(struct super_block *sb)
/*
* wait for asynchronous fs operations to finish before going further
*/
- async_synchronize_full_special(&sb->s_async_list);
+ async_synchronize_full_domain(&sb->s_async_list);
/* bad name - it should be evict_inodes() */
invalidate_inodes(sb);
@@ -470,7 +470,7 @@ restart:
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
- async_synchronize_full_special(&sb->s_async_list);
+ async_synchronize_full_domain(&sb->s_async_list);
if (sb->s_root && (wait || sb->s_dirt))
sb->s_op->sync_fs(sb, wait);
up_read(&sb->s_umount);
diff --git a/include/linux/async.h b/include/linux/async.h
index c4ecacd0b327..68a9530196f2 100644
--- a/include/linux/async.h
+++ b/include/linux/async.h
@@ -17,9 +17,11 @@ typedef u64 async_cookie_t;
typedef void (async_func_ptr) (void *data, async_cookie_t cookie);
extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data);
-extern async_cookie_t async_schedule_special(async_func_ptr *ptr, void *data, struct list_head *list);
+extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
+ struct list_head *list);
extern void async_synchronize_full(void);
-extern void async_synchronize_full_special(struct list_head *list);
+extern void async_synchronize_full_domain(struct list_head *list);
extern void async_synchronize_cookie(async_cookie_t cookie);
-extern void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *list);
+extern void async_synchronize_cookie_domain(async_cookie_t cookie,
+ struct list_head *list);
diff --git a/kernel/async.c b/kernel/async.c
index 67a2be71f517..f565891f2c9b 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -54,6 +54,7 @@ asynchronous and synchronous parts of the kernel.
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/kthread.h>
+#include <linux/delay.h>
#include <asm/atomic.h>
static async_cookie_t next_cookie = 1;
@@ -132,8 +133,7 @@ static void run_one_entry(void)
entry = list_first_entry(&async_pending, struct async_entry, list);
/* 2) move it to the running queue */
- list_del(&entry->list);
- list_add_tail(&entry->list, &async_running);
+ list_move_tail(&entry->list, entry->running);
spin_unlock_irqrestore(&async_lock, flags);
/* 3) run it (and print duration)*/
@@ -208,18 +208,44 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct l
return newcookie;
}
+/**
+ * async_schedule - schedule a function for asynchronous execution
+ * @ptr: function to execute asynchronously
+ * @data: data pointer to pass to the function
+ *
+ * Returns an async_cookie_t that may be used for checkpointing later.
+ * Note: This function may be called from atomic or non-atomic contexts.
+ */
async_cookie_t async_schedule(async_func_ptr *ptr, void *data)
{
- return __async_schedule(ptr, data, &async_pending);
+ return __async_schedule(ptr, data, &async_running);
}
EXPORT_SYMBOL_GPL(async_schedule);
-async_cookie_t async_schedule_special(async_func_ptr *ptr, void *data, struct list_head *running)
+/**
+ * async_schedule_domain - schedule a function for asynchronous execution within a certain domain
+ * @ptr: function to execute asynchronously
+ * @data: data pointer to pass to the function
+ * @running: running list for the domain
+ *
+ * Returns an async_cookie_t that may be used for checkpointing later.
+ * @running may be used in the async_synchronize_*_domain() functions
+ * to wait within a certain synchronization domain rather than globally.
+ * A synchronization domain is specified via the running queue @running to use.
+ * Note: This function may be called from atomic or non-atomic contexts.
+ */
+async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
+ struct list_head *running)
{
return __async_schedule(ptr, data, running);
}
-EXPORT_SYMBOL_GPL(async_schedule_special);
+EXPORT_SYMBOL_GPL(async_schedule_domain);
+/**
+ * async_synchronize_full - synchronize all asynchronous function calls
+ *
+ * This function waits until all asynchronous function calls have been done.
+ */
void async_synchronize_full(void)
{
do {
@@ -228,13 +254,30 @@ void async_synchronize_full(void)
}
EXPORT_SYMBOL_GPL(async_synchronize_full);
-void async_synchronize_full_special(struct list_head *list)
+/**
+ * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain
+ * @list: running list to synchronize on
+ *
+ * This function waits until all asynchronous function calls for the
+ * synchronization domain specified by the running list @list have been done.
+ */
+void async_synchronize_full_domain(struct list_head *list)
{
- async_synchronize_cookie_special(next_cookie, list);
+ async_synchronize_cookie_domain(next_cookie, list);
}
-EXPORT_SYMBOL_GPL(async_synchronize_full_special);
+EXPORT_SYMBOL_GPL(async_synchronize_full_domain);
-void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *running)
+/**
+ * async_synchronize_cookie_domain - synchronize asynchronous function calls within a certain domain with cookie checkpointing
+ * @cookie: async_cookie_t to use as checkpoint
+ * @running: running list to synchronize on
+ *
+ * This function waits until all asynchronous function calls for the
+ * synchronization domain specified by the running list @list submitted
+ * prior to @cookie have been done.
+ */
+void async_synchronize_cookie_domain(async_cookie_t cookie,
+ struct list_head *running)
{
ktime_t starttime, delta, endtime;
@@ -254,11 +297,18 @@ void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *r
(long long)ktime_to_ns(delta) >> 10);
}
}
-EXPORT_SYMBOL_GPL(async_synchronize_cookie_special);
+EXPORT_SYMBOL_GPL(async_synchronize_cookie_domain);
+/**
+ * async_synchronize_cookie - synchronize asynchronous function calls with cookie checkpointing
+ * @cookie: async_cookie_t to use as checkpoint
+ *
+ * This function waits until all asynchronous function calls prior to @cookie
+ * have been done.
+ */
void async_synchronize_cookie(async_cookie_t cookie)
{
- async_synchronize_cookie_special(cookie, &async_running);
+ async_synchronize_cookie_domain(cookie, &async_running);
}
EXPORT_SYMBOL_GPL(async_synchronize_cookie);
@@ -319,7 +369,11 @@ static int async_manager_thread(void *unused)
ec = atomic_read(&entry_count);
while (tc < ec && tc < MAX_THREADS) {
- kthread_run(async_thread, NULL, "async/%i", tc);
+ if (IS_ERR(kthread_run(async_thread, NULL, "async/%i",
+ tc))) {
+ msleep(100);
+ continue;
+ }
atomic_inc(&thread_count);
tc++;
}
@@ -334,7 +388,9 @@ static int async_manager_thread(void *unused)
static int __init async_init(void)
{
if (async_enabled)
- kthread_run(async_manager_thread, NULL, "async/mgr");
+ if (IS_ERR(kthread_run(async_manager_thread, NULL,
+ "async/mgr")))
+ async_enabled = 0;
return 0;
}