linux-kernel - Re: [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support

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]

Date:	Tue, 30 Jun 2009 15:39:52 -0400 (EDT)
From:	Christoph Lameter <cl@...ux-foundation.org>
To:	Ingo Molnar <mingo@...e.hu>
cc:	Andrew Morton <akpm@...ux-foundation.org>, tj@...nel.org,
	linux-kernel@...r.kernel.org, x86@...nel.org,
	linux-arch@...r.kernel.org, andi@...stfloor.org, hpa@...or.com,
	tglx@...utronix.de
Subject: Re: [PATCHSET] percpu: generalize first chunk allocators and improve
 lpage NUMA support

On Tue, 30 Jun 2009, Ingo Molnar wrote:

> Yeah, it's a bug for something like a virtual environment which
> boots generic kernels that might have 64 possible CPUs (on a true
> 64-way system), but which will have fewer in practice.

A machine (and a virtual environment) can indicate via the BIOS tables or
ACPI that there are less "possible" cpus. That is actually very common.

The difference between actual and possible cpus only has to be the number
of processors that could be brought up later. In a regular system that is
pretty much zero. In a fancy system with actual hotpluggable cpus there
would be a difference but usually the number of hotpluggable cpus is
minimal.

--
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/