From owner-freebsd-current Sat Jul 25 17:12:49 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA17986 for freebsd-current-outgoing; Sat, 25 Jul 1998 17:12:49 -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 RAA17980 for ; Sat, 25 Jul 1998 17:12:48 -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 RAA27997; Sat, 25 Jul 1998 17:10:54 -0700 (PDT) Message-Id: <199807260010.RAA27997@implode.root.com> To: Brian Feldman cc: freebsd-current@FreeBSD.ORG Subject: Re: New LINT options: what is VM coloring? In-reply-to: Your message of "Sat, 25 Jul 1998 18:11:47 EDT." From: David Greenman Reply-To: dg@root.com Date: Sat, 25 Jul 1998 17:10:54 -0700 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >Would anyone mind letting me in on exactly what "VM coloring" is, and >especially whether or not I should define one of these?: ># Options for the VM subsystem >#options PQ_NOOPT # No coloring >options PQ_LARGECACHE # color for 512k/16k cache >#options PQ_HUGECACHE # color for 1024k/16k cache >As far as I can tell, it would seem these would be options to set certain >parameters to optimal as far as the VM subsystem goes, and if so, is it >safe to use one? 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). -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