Re: [PATCH RESEND] Fix a dead loop in async_synchronize_full()

From: Christian Kujau
Date: Mon Jul 16 2012 - 14:32:17 EST


On Thu, 12 Jul 2012 at 17:56, Li Zhong wrote:
> On Wed, 2012-07-11 at 15:50 -0700, Dan Williams wrote:
> > On Wed, Jul 11, 2012 at 3:42 PM, Andrew Morton
> > <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > > The patch is fairly wordwrapped - please fix up your email client.
> > >
> > > More seriously, it does not apply to linux-next due to some fairly
> > > significant changes which have been sitting in Dan's tree since May.
> > > What's going on?
> > >
> >
> > Those changes missed the 3.5 merge window, but now that they have
> > Arjan's ack they should head upstream via James for 3.6. Right now
> > they are on his pending [1] branch.
> >
> > As far as the comment:
> >
> > > It seems async_synchronize_full() wants to synchronize all entries in
> > > all running lists(domains), so maybe we could just check the entry_count
> > > to know whether all works are finished.
> >
> > ...at first glance this is what the new async patches achieve.
> > async_synchronize_full should now sync work across all domains, but if
> > you can reproduce this bug it would be nice to confirm that the
> > pending changes fix it.
> >
>
> I have tested your pending patches, they fix the problem here.
>
> But with ASYNC_DOMAIN_EXCLUSIVE added for the domains defined on the
> stack, I think we lack a function that could wait for all the works in
> all domains (however, maybe actually we don't need such an interface).
>
> Also, I think it's not good to exclude them from
> async_synchronize_full() just because they are defined on the stack.

Is this still scheduled to go into 3.5? I'm asking because -rc7 has been
released and does not contain this fix. W/o this fix, my powerpc system
won't boot[0] :-\

Thanks,
Christian.

[0] http://nerdbynature.de/bits/3.5.0-rc5/soft_lockup/
--
BOFH excuse #28:

CPU radiator broken
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/