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authorArjan van de Ven <arjan@linux.intel.com>2009-01-11 15:35:01 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-12 16:39:58 -0800
commit37a76bd4f1b716949fc38a6842e89f0ccb8384d0 (patch)
tree6537cab6fb0e1a9508d34ca95b25808866bf04af /kernel/async.c
parentd32ad102c6d748b510fd89f1af4232eac1be8732 (diff)
downloadvexpress-lsk-37a76bd4f1b716949fc38a6842e89f0ccb8384d0.tar.gz
async: fix __lowest_in_progress()
At 37000 feet somewhere near Greenland I woke up from a half-sleep with the realisation that __lowest_in_progress() is buggy. After landing I checked and there were indeed 2 problems with it; this patch fixes both: * The order of the list checks was wrong * The locking was not correct. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/async.c')
-rw-r--r--kernel/async.c21
1 files changed, 16 insertions, 5 deletions
diff --git a/kernel/async.c b/kernel/async.c
index f286e9f2b73..608b32b4281 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -90,12 +90,12 @@ extern int initcall_debug;
static async_cookie_t __lowest_in_progress(struct list_head *running)
{
struct async_entry *entry;
- if (!list_empty(&async_pending)) {
- entry = list_first_entry(&async_pending,
+ if (!list_empty(running)) {
+ entry = list_first_entry(running,
struct async_entry, list);
return entry->cookie;
- } else if (!list_empty(running)) {
- entry = list_first_entry(running,
+ } else if (!list_empty(&async_pending)) {
+ entry = list_first_entry(&async_pending,
struct async_entry, list);
return entry->cookie;
} else {
@@ -104,6 +104,17 @@ static async_cookie_t __lowest_in_progress(struct list_head *running)
}
}
+
+static async_cookie_t lowest_in_progress(struct list_head *running)
+{
+ unsigned long flags;
+ async_cookie_t ret;
+
+ spin_lock_irqsave(&async_lock, flags);
+ ret = __lowest_in_progress(running);
+ spin_unlock_irqrestore(&async_lock, flags);
+ return ret;
+}
/*
* pick the first pending entry and run it
*/
@@ -229,7 +240,7 @@ void async_synchronize_cookie_special(async_cookie_t cookie, struct list_head *r
starttime = ktime_get();
}
- wait_event(async_done, __lowest_in_progress(running) >= cookie);
+ wait_event(async_done, lowest_in_progress(running) >= cookie);
if (initcall_debug && system_state == SYSTEM_BOOTING) {
endtime = ktime_get();