linux-kernel - Re: [PATCH v5 10/16] x86/mce: enable Hygon support to MCE infrastructure

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Date:   Thu, 6 Sep 2018 14:29:56 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Pu Wen <puwen@...on.cn>
Cc:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        x86@...nel.org, thomas.lendacky@....com, pbonzini@...hat.com,
        tony.luck@...el.com, linux-kernel@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-edac@...r.kernel.org
Subject: Re: [PATCH v5 10/16] x86/mce: enable Hygon support to MCE
 infrastructure

On Thu, Sep 06, 2018 at 07:40:52PM +0800, Pu Wen wrote:
> The first is the compilation test. Test the kernel with both MCE selected
> and unselected to see if is the compiling process successful or not.

This is a kernel compile test - it has nothing to do with actual machine
testing.

> The other test is functionality test. For example, during the MCE BIOS
> development, to see if the MCE functions OK, it may need to select and
> unselect MCE in kernel for double checking.

Say what now?! What testing do you do if you boot a kernel which doesn't
even use the functionality you're testing?!

> Actually in normal use scenario and in real product the MCE should be
> always selected.

It better be!

> To ensure this, I think there are two ways as below:
> - Select X86_MCE_AMD in CPU_SUP_HYGON config entry, it also cater to the
>   first test scenario, but meanwhile lacks flexibility.
> - The linux distros(Ubuntu, CentOS, etc) ensure that X86_MCE_AMD is
>   selected to the default config file, and indeed they do.
> Which way is better?

The first way but change that dependency to CPU_SUP_AMD because there
are people building their own kernels and don't run distro configs. And
you need CPU_SUP_AMD because you're using their code.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.