linux-kernel - Re: [PATCH] x86: add /proc/cpuinfo/physical id quirks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4A8DFD92.3060502@zytor.com>
Date:	Thu, 20 Aug 2009 18:51:14 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Andi Kleen <andi@...stfloor.org>
CC:	Suresh Siddha <suresh.b.siddha@...el.com>,
	Alex Chiang <achiang@...com>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86: add /proc/cpuinfo/physical id quirks

On 08/20/2009 05:32 PM, Andi Kleen wrote:
>> I agree... if this ID is used for topology detection, we shouldn't
>> replace it arbitrarily with information from BIOS just to hope that it
>> matches the motherboard stencil.  *Furthermore*, there is no reason why
>> motherboard stencilAs are purely numeric... consider the rather obvious
>> case of two rows of four CPUs; they may have CPU slots labelled A1, A2,
>> A3, A4, B1, B2, B3, B4.  It might very well be the right thing to
>> support arbitrary strings for platforms we recognize.
> 
> Maintaining a manual mapping to strings in the kernel to such strings 
> would be just crazy. You would need a new entry for basically
> every system.
> 
> The reason to correct SOCKETID is that it it is output on errors.
> If it is numerical and you know it's wrong you can correct it,
> and then you can identify the right CPU. Otherwise you lose.
> 

You're not making any sense.  You seem to imply that restricting it to a
numerical ID makes it somehow easier, but it's *the same problem*.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/