From owner-freebsd-current Sun Jul 26 03:23:43 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA05638 for freebsd-current-outgoing; Sun, 26 Jul 1998 03:23:43 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from implode.root.com (implode.root.com [198.145.90.17]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id DAA05595 for ; Sun, 26 Jul 1998 03:22:41 -0700 (PDT) (envelope-from root@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.5/8.8.5) with ESMTP id DAA07327; Sun, 26 Jul 1998 03:20:23 -0700 (PDT) Message-Id: <199807261020.DAA07327@implode.root.com> To: Andreas Klemm cc: Brian Feldman , freebsd-current@FreeBSD.ORG Subject: Re: New LINT options: what is VM coloring? In-reply-to: Your message of "Sun, 26 Jul 1998 11:24:01 +0200." <19980726112401.A5570@klemm.gtn.com> From: David Greenman Reply-To: dg@root.com Date: Sun, 26 Jul 1998 03:20:23 -0700 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >On Sat, Jul 25, 1998 at 05:10:54PM -0700, David Greenman wrote: >> Page coloring is the process of allocating pages that have physical >> alignment that provides optimal utilization of the memory cache. This can >> be a big win for direct-mapped caches (e.g. most Pentium L2 caches), but >> loses effectiveness with set-associative caches (e.g. Pentium Pro, which >> has a set size of 4). > >Do you think it would be better to turn PQ off using: > > options PQ_NOOPT # No coloring You mean in the Pentium Pro case? No, page coloring has basically no overhead and can only help - even with associative caches. I think the "PQ_NOOPT" option is only for performance comparison/testing. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message