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Date:   Wed, 6 Nov 2019 18:42:13 +0100 (CET)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Oleg Nesterov <oleg@redhat.com>
cc:     Florian Weimer <fweimer@redhat.com>, Shawn Landden <shawn@git.icu>,
        libc-alpha@sourceware.org, linux-api@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Deepa Dinamani <deepa.kernel@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Keith Packard <keithp@keithp.com>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: handle_exit_race && PF_EXITING
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On Wed, 6 Nov 2019, Oleg Nesterov wrote:
> 
> I think that (with or without this fix) handle_exit_race() logic needs
> cleanups, there is no reason for get_futex_value_locked(), we can drop
> ->pi_lock right after we see PF_EXITPIDONE. Lets discuss this later.

Which still is in atomic because the hash bucket lock is held, ergo
get_futex_value_locked() needs to stay for now.

So the only thing we could do is to reduce the pi_lock held section a bit.

Thanks,

	tglx