linux-kernel - Re: [RFC 00/15] x86_64: Optimize percpu accesses

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: <487663C4.6040309@zytor.com>
Date:	Thu, 10 Jul 2008 15:32:20 -0400
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Mike Travis <travis@....com>
CC:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jack Steiner <steiner@....com>, linux-kernel@...r.kernel.org,
	Arjan van de Ven <arjan@...radead.org>
Subject: Re: [RFC 00/15] x86_64: Optimize percpu accesses

Mike Travis wrote:
> 
> The biggest growth came from moving all the xxx[NR_CPUS] arrays into
> the per cpu area.  So you free up a huge amount of unused memory when
> the NR_CPUS count starts getting into the ozone layer.  4k now, 16k
> real soon now, ??? future?
> 

Even (or perhaps especially) so, allocating the percpu area in 2 MB 
increments is a total nonstarter.  It hurts the small, common 
configurations way too much.  For SGI, it's probably fine.

	-hpa
--
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/