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From:   Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date:   Thu, 20 Dec 2018 19:20:03 +0000
Message-ID: <CADVatmMiwaOQ2R43CArk1s5=bxr7MUgzuDb0DfQO_LKLH_r-ZQ@mail.gmail.com>
Subject: Re: [PATCH 4.14 21/72] locking/qspinlock: Ensure node is initialised
 before updating prev->next
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Will Deacon <will.deacon@arm.com>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>,
        Stable <stable@vger.kernel.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Sasha Levin <sashal@kernel.org>
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On Thu, Dec 20, 2018 at 3:41 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Thu, Dec 20, 2018 at 12:19:04PM +0000, Sudip Mukherjee wrote:
> > Hi Greg,
> >
> > On Thu, Dec 20, 2018 at 9:27 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > 4.14-stable review patch.  If anyone has any objections, please let me know.
> > >
> > > ------------------
> > >
> > > commit 95bcade33a8af38755c9b0636e36a36ad3789fe6 upstream.
> >
> > It seems 9d4646d14d51 ("locking/qspinlock: Elide back-to-back RELEASE
> > operations with smp_wmb()") is improving the fix. Is it worth to take
> > this also?
>
> If someone could test that this really does help things out, I would be
> glad to take it :)

I can test if Will shows me how to test the improvement, but it might
be easier for him to test than showing me :)


-- 
Regards
Sudip