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Date:   Tue, 20 Jun 2023 10:47:44 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     LKML <linux-kernel@vger.kernel.org>, x86@kernel.org,
        Mario Limonciello <mario.limonciello@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Tony Battersby <tonyb@cybernetics.com>,
        Ashok Raj <ashok.raj@linux.intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Arjan van de Veen <arjan@linux.intel.com>,
        Eric Biederman <ebiederm@xmission.com>
Subject: Re: [patch v3 3/7] x86/smp: Remove pointless wmb()s from
 native_stop_other_cpus()
Message-ID: <20230620084744.GUZJFnsClkvsGQmnRs@fat_crate.local>
References: <20230615190036.898273129@linutronix.de>
 <20230615193330.378358382@linutronix.de>
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On Thu, Jun 15, 2023 at 10:33:54PM +0200, Thomas Gleixner wrote:
> The wmb()s before sending the IPIs are not synchronizing anything.
> 
> If at all then the apic IPI functions have to provide or act as appropriate
> barriers.
> 
> Remove these cargo cult barriers which have no explanation of what they are
> synchronizing.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> V3: Remove second instance and reword changelog - PeterZ
> ---
>  arch/x86/kernel/smp.c |    6 ------
>  1 file changed, 6 deletions(-)

Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette