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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon, 3 Dec 2018 09:06:18 -0800
Message-ID: <CAHk-=wibyrfrpRoyGRwFrLZvrxAg=j5ueTje=4GckJcJSy-pwg@mail.gmail.com>
Subject: Re: [PATCH] Revert "exec: make de_thread() freezable (was: Re: Linux 4.20-rc4)
To:     mhocko@kernel.org
Cc:     pavel@ucw.cz, Oleg Nesterov <oleg@redhat.com>,
        Ingo Molnar <mingo@kernel.org>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        rafael.j.wysocki@intel.com, chanho.min@lge.com,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
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On Mon, Dec 3, 2018 at 6:17 AM Michal Hocko <mhocko@kernel.org> wrote:
>
> This argument just doesn't make any sense. Rare bugs are maybe even more
> annoying because you do not expect them to happen.

Absolutely.

And valid lockdep complaints are a real issue too.

So I don't think there's any question that this should be reverted,
the only question is whether I take the revert directly or get it from
the PM tree.

It does sound like the de_thread() behavior needs more work. Maybe,
for example, we need to make it clear that zapped threads are *not*
frozen, and instead the freezer will wait for them to exit?

Hmm?

                      Linus