linux-kernel - Re: [PATCH RESEND 4/5] x86/MCE: Make number of MCA banks per

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Message-ID: <20190408205013.GN15689@zn.tnic>
Date:   Mon, 8 Apr 2019 22:50:13 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Luck, Tony" <tony.luck@...el.com>
Cc:     "Ghannam, Yazen" <Yazen.Ghannam@....com>,
        "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>
Subject: Re: [PATCH RESEND 4/5] x86/MCE: Make number of MCA banks per_cpu

On Mon, Apr 08, 2019 at 08:42:36PM +0000, Luck, Tony wrote:
> > Actually, it should not be exported at all. A function returning the num
> > banks is better instead.
> 
> Are all the places it is used in non-pre-emptible sections of code? Looping
> in the CMCI and #MC handlers should be fine. But do we need get_cpu()/put_cpu()
> in any places?

That export is needed only in the mce injector. Actually, it would be
much cleaner if the injector would find out the count straight from the
MSR as it does now, but be changed to do rdmsr_on_cpu() now, since can
have different num_banks on a CPU.

-- 
Regards/Gruss,
    Boris.

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