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

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Message-ID: <SN6PR12MB2639F3E98157872E7C046705F82C0@SN6PR12MB2639.namprd12.prod.outlook.com>
Date:   Mon, 8 Apr 2019 22:48:34 +0000
From:   "Ghannam, Yazen" <Yazen.Ghannam@....com>
To:     Borislav Petkov <bp@...en8.de>, "Luck, Tony" <tony.luck@...el.com>
CC:     "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

> -----Original Message-----
> From: linux-edac-owner@...r.kernel.org <linux-edac-owner@...r.kernel.org> On Behalf Of Borislav Petkov
> Sent: Monday, April 8, 2019 3:50 PM
> To: Luck, Tony <tony.luck@...el.com>
> Cc: Ghannam, Yazen <Yazen.Ghannam@....com>; linux-edac@...r.kernel.org; linux-kernel@...r.kernel.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.
> 

Okay, so drop the export and leave the injector code as-is (it's already doing a rdmsrl_on_cpu()).

Is that okay?

Thanks,
Yazen