linux-kernel - RE: [PATCH v2 10/16] x86/mce: Separate global and per-CPU quirks

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Message-ID: <CY8PR11MB71348215C3D43B73DA4B3BA389C42@CY8PR11MB7134.namprd11.prod.outlook.com>
Date: Thu, 20 Feb 2025 01:27:03 +0000
From: "Zhuo, Qiuxu" <qiuxu.zhuo@...el.com>
To: Yazen Ghannam <yazen.ghannam@....com>
CC: "x86@...nel.org" <x86@...nel.org>, "Luck, Tony" <tony.luck@...el.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
	"Smita.KoralahalliChannabasappa@....com"
	<Smita.KoralahalliChannabasappa@....com>
Subject: RE: [PATCH v2 10/16] x86/mce: Separate global and per-CPU quirks

> From: Yazen Ghannam <yazen.ghannam@....com>
> [...]
> > Is it better to add the following description here? So that it's clear
> > we don't apply the quirks for older CPUs.
> >
> >     Older CPUs (prior to family 6) can't reach this point and already return
> early
> >     due to the check of __mcheck_cpu_ancient_init().
> >
> 
> I don't know. As you said, the older CPUs don't enter this code, so why refer
> to them at all?
> 

As the following check "if (c->x86_vfm < INTEL_NEHALEM_EP ..." includes older 
CPUs (e.g. family == 5). Stating that older CPUs don't reach this point makes it 
clear that the quirks are not applied to them.

> > > +	 */
> > > +	if (c->x86_vfm < INTEL_NEHALEM_EP &&
> > > this_cpu_read(mce_num_banks))
> > > +		this_cpu_ptr(mce_banks_array)[0].init = false; }
> > > +
> > [...]
> >
> > LGTM. Thanks.
> >
> >     Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
> >
> 
> Thanks,
> Yazen