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

Uli Luckas
2007-06-26T13:06:57Z

On Tuesday, 19. June 2007, Uli Luckas wrote:
> Hi,
> is there anything in the way of apllying this patch?
>
Please, can someone tell me what it takes to get a jffs2 bug fix into the
kernel? Or even reviewed? This patch should even get into 2.6.22. Am I doing
something wrong here?

Regards
Uli

> 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;
> >                 }