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References: <20220406142819.730238-1-guoren@kernel.org>
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From:   Max Filippov <jcmvbkbc@gmail.com>
Date:   Wed, 6 Apr 2022 20:35:12 -0700
Message-ID: <CAMo8BfK6uo5fPCbo8Wp3oRYOUXoz0jv_zJMHuVHhFgh3DSSqNQ@mail.gmail.com>
Subject: Re: [PATCH V3] xtensa: patch_text: Fixup last cpu should be master
To:     Guo Ren <guoren@kernel.org>
Cc:     Arnd Bergmann <arnd@arndb.de>, Chris Zankel <chris@zankel.net>,
        Linux-Arch <linux-arch@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "open list:TENSILICA XTENSA PORT (xtensa)" 
        <linux-xtensa@linux-xtensa.org>,
        Guo Ren <guoren@linux.alibaba.com>,
        Masami Hiramatsu <mhiramat@kernel.org>, stable@vger.kernel.org
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On Wed, Apr 6, 2022 at 7:28 AM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> These patch_text implementations are using stop_machine_cpuslocked
> infrastructure with atomic cpu_count. The original idea: When the
> master CPU patch_text, the others should wait for it. But current
> implementation is using the first CPU as master, which couldn't
> guarantee the remaining CPUs are waiting. This patch changes the
> last CPU as the master to solve the potential risk.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: <stable@vger.kernel.org>
> ---
>  arch/xtensa/kernel/jump_label.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Thanks. Applied to my xtensa tree.

-- Max