Re: [PATCH] Revert "exec: make de_thread() freezable (was: Re: Linux 4.20-rc4)

From: Michal Hocko
Date: Mon Dec 03 2018 - 07:39:05 EST


On Mon 03-12-18 13:31:49, Oleg Nesterov wrote:
> On 12/03, Michal Hocko wrote:
> >
> > Now, I wouldn't mind to revert this because the code is really old and
> > we haven't seen many bug reports about failing suspend yet. But what is
> > the actual plan to make this work properly?
>
> I don't see a simple solution...
>
> But we need to fix exec/de_thread anyway, then we can probably reconsider
> this patch.

My concern is that de_thread fix might be too disruptive for stable
kernels while we might want to have a simple enough fix for the the
suspend issue in the meantime. That was actually the primary reason I've
acked the hack even though I didn't like it.

So can we find a way to shut the lockdep up when this is not really a
deadlock? Or maybe this really is one and then we need a real fix for
stable as well.
--
Michal Hocko
SUSE Labs