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From:   Doug Anderson <dianders@chromium.org>
Date:   Fri, 5 Aug 2022 10:14:36 -0700
Message-ID: <CAD=FV=X7FnrwHSedA=1xJsrfSgQZcqu0YEAKrfoJC6BhDc-gFA@mail.gmail.com>
Subject: Re: [PATCH v5] locking/rwsem: Make handoff bit handling more consistent
To:     Hillf Danton <hdanton@sina.com>
Cc:     Waiman Long <longman@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Will Deacon <will@kernel.org>,
        Davidlohr Bueso <dave@stgolabs.net>, MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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Hi,

On Fri, Jul 22, 2022 at 5:17 PM Hillf Danton <hdanton@sina.com> wrote:
>
> On Fri, 22 Jul 2022 07:02:42 -0700 Doug Anderson wrote:
> >
> > Thanks! I added this diff to your previous diff and my simple test
> > still passes and I don't see your WARN_ON triggered.
>
> Thanks!
> >
> > How do we move forward? Are you going to officially submit a patch
> > with both of your diffs squashed together? Are we waiting for
> > additional review from someone?
>
> Given it is not unusual for us to miss anything important, lets take
> a RWSEM_WAIT_TIMEOUT nap now or two.

It appears that another fix has landed in the meantime. Commit
6eebd5fb2083 ("locking/rwsem: Allow slowpath writer to ignore handoff
bit if not set by first waiter").

...unfortunately with that patch my test cases still hangs. :(