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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 5 May 2022 13:05:11 +0200
Message-ID: <CAK8P3a2fLg9DJvQeOAFhRQk-O72PAhJ77CLQ+Pz_Vvh1WV1APQ@mail.gmail.com>
Subject: Re: [PATCH v4 2/7] asm-generic: qspinlock: Indicate the use of
 mixed-size atomics
To:     =?UTF-8?Q?Heiko_St=C3=BCbner?= <heiko@sntech.de>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Guo Ren <guoren@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
        Waiman Long <longman@redhat.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Jonas Bonn <jonas@southpole.se>,
        Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
        Stafford Horne <shorne@gmail.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Greg KH <gregkh@linuxfoundation.org>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
        "Maciej W. Rozycki" <macro@orcam.me.uk>,
        Jisheng Zhang <jszhang@kernel.org>, linux-csky@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Openrisc <openrisc@lists.librecores.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Palmer Dabbelt <palmer@rivosinc.com>
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On Wed, May 4, 2022 at 2:02 PM Heiko Stübner <heiko@sntech.de> wrote:
> > index d74b13825501..95be3f3c28b5 100644
> > --- a/include/asm-generic/qspinlock.h
> > +++ b/include/asm-generic/qspinlock.h
> > @@ -2,6 +2,37 @@
> >  /*
> >   * Queued spinlock
> >   *
> > + * A 'generic' spinlock implementation that is based on MCS locks. An
>
> _For_ an architecture that's ... ?
>
> > + * architecture that's looking for a 'generic' spinlock, please first consider
> > + * ticket-lock.h and only come looking here when you've considered all the
> > + * constraints below and can show your hardware does actually perform better
> > + * with qspinlock.
> > + *
> > + *
>
> double empty line is probably not necessary
>

I've applied the series to the asm-generic tree now, and edited both the above
as you suggested in the process, to save Palmer the v5.

         Arnd