[PATCH] jffs2_gcd_mtd3, Stopping kernel threads timed out

Uli Luckas
2007-06-12T12:13:02Z

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Hi
We experience the following problem when our board tries to suspend:

Jun 7 18:32:21 constin kernel: [ 2085.350000] Stopping tasks ...
Jun 7 18:32:21 constin kernel: [ 2105.410000] Stopping kernel threads timed
out after 20 seconds (1 tasks refusing to freeze):
Jun 7 18:32:21 constin kernel: [ 2105.410000] jffs2_gcd_mtd3
Jun 7 18:32:21 constin kernel: [ 2105.410000] Restarting tasks ... <4>
Strange, jffs2_gcd_mtd3 not stopped
Jun 7 18:32:21 constin kernel: [ 2105.440000] done.

The problem seems to happen, when suspend kicks in, after the call to
try_to_freeze and before the while loop in jffs2_garbage_collect_thread.

The pending freeze will cause signal_pending to return true until the
attempted suspend is over and thereby the while loop won't terminate until
the suspend times out.

This patch will call try_to_freeze from within the while loop and adds an
extra check for jffs2_thread_should_wake before we actually do the GC to
avoid calling jffs2_garbage_collect_pass at every wakeup.

If there are no objections, please apply and push to mainline.

Signed-off-by: Uli Luckas <u.luckas@road.de>

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diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
index 888f236..43a2fc8 100644
--- a/fs/jffs2/background.c
+++ b/fs/jffs2/background.c
@@ -96,9 +96,6 @@ static int jffs2_garbage_collect_thread(void *_c)
schedule();
}

- if (try_to_freeze())
- continue;
-
/* This thread is purely an optimisation. But if it runs when
other things could be running, it actually makes things a
lot worse. Use yield() and put it at the back of the runqueue
@@ -113,6 +110,9 @@ static int jffs2_garbage_collect_thread(void *_c)
siginfo_t info;
unsigned long signr;

+ if (try_to_freeze())
+ continue;
+
signr = dequeue_signal_lock(current, &current->blocked, &info);

switch(signr) {
@@ -137,7 +137,7 @@ static int jffs2_garbage_collect_thread(void *_c)
disallow_signal(SIGHUP);

D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n"));
- if (jffs2_garbage_collect_pass(c) == -ENOSPC) {
+ if (jffs2_thread_should_wake(c) && jffs2_garbage_collect_pass(c) == -ENOSPC) {
printk(KERN_NOTICE "No space for garbage collection. Aborting GC thread\n");
goto die;
}