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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 27 Aug 2017 14:42:11 -0700
Message-ID: <CA+55aFzmQe+Q60jjEKmu=Jv-wUCgeAeErp6ANbSmfO45j7Q8ZA@mail.gmail.com>
Subject: Re: [PATCH 2/2 v2] sched/wait: Introduce lock breaker in wake_up_page_bit
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To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>, Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@linux.intel.com>, Kan Liang <kan.liang@intel.com>, Andrew Morton <akpm@linux-foundation.org>, Johannes Weiner <hannes@cmpxchg.org>, Jan Kara <jack@suse.cz>, Christopher Lameter <cl@linux.com>, "Eric W . Biederman" <ebiederm@xmission.com>, Davidlohr Bueso <dave@stgolabs.net>, linux-mm <linux-mm@kvack.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>

On Sun, Aug 27, 2017 at 2:40 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> End result: page is unlocked, CPU3 is waiting, nothing will wake CPU3 up.

Not CPU3. CPU3 was the waker. It's thread 2 that is waiting and never
got woken up, of course.

Other than that, the scenario still looks real to me.

Ideas?

                 Linus

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