From owner-cvs-all Sat May 23 23:09:43 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id XAA19550 for cvs-all-outgoing; Sat, 23 May 1998 23:09:43 -0700 (PDT) (envelope-from owner-cvs-all@FreeBSD.ORG) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id XAA19515; Sat, 23 May 1998 23:09:28 -0700 (PDT) (envelope-from toor@dyson.iquest.net) Received: (from root@localhost) by dyson.iquest.net (8.8.8/8.8.8) id BAA02858; Sun, 24 May 1998 01:09:16 -0500 (EST) (envelope-from toor) From: "John S. Dyson" Message-Id: <199805240609.BAA02858@dyson.iquest.net> Subject: Re: cvs commit: src/sys/vm vm_page.h In-Reply-To: <19980524153244.J353@freebie.lemis.com> from Greg Lehey at "May 24, 98 03:32:44 pm" To: grog@lemis.com (Greg Lehey) Date: Sun, 24 May 1998 01:09:16 -0500 (EST) Cc: dyson@FreeBSD.ORG, cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG, cvs-sys@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk > On Sat, 23 May 1998 at 21:25:29 -0700, John Dyson wrote: > > dyson 1998/05/23 21:25:28 PDT > > > > Modified files: > > sys/vm vm_page.h > > Log: > > Support a 16K first level cache for 512K 2nd level. Also, add support > > for 1MB 2nd level cache. > > Does this mean that previously we didn't use the full 1MB second level > cache? > No, it is just a coloring (optimization) issue. Once you color to 256K, coloring more only gives a small incremental improvement over a barely measurable one to begin with. (Actually, the improvement *can* be significant, but the improvement isn't measurable under most conditions.) The support for the 1st level cache isn't too important anyway, since it is often a multi-way associative one, and such caches don't see an advantage when coloring. PPro machines support a 4way 2nd level cache, so fully coloring the cache isn't too valuable. It is most valuable to color a P5 2nd level cache, that is usually direct mapped. John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message