Re: [PATCH] jffs2_gcd_mtd3, Stopping kernel threads timed out

Uli Luckas
2007-06-19T09:50:05Z

Hi,
is there anything in the way of apllying this patch?

Regards
Uli

On Thursday, 14. June 2007, Uli Luckas wrote:
> 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>
>
> diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
> index 888f236..f953824 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 +137,8 @@ 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;
>                 }