From owner-freebsd-hackers Sat Apr 22 23:26: 3 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 416BF37B795 for ; Sat, 22 Apr 2000 23:26:00 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id XAA58076; Sat, 22 Apr 2000 23:25:52 -0700 (PDT) (envelope-from dillon) Date: Sat, 22 Apr 2000 23:25:52 -0700 (PDT) From: Matthew Dillon Message-Id: <200004230625.XAA58076@apollo.backplane.com> To: Kent Stewart Cc: Michael Bacarella , Alfred Perlstein , Kevin Day , hackers@FreeBSD.ORG Subject: Re: Double buffered cp(1) References: <200004221736.KAA55484@apollo.backplane.com> <3901F277.66DDDDAF@3-cities.com> <200004222317.QAA56834@apollo.backplane.com> <39026874.F652A405@3-cities.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :You are right but that is because I haven't started keeping record on :4.0-Stable and we were comparing apples and oranges. A buildworld of :3.4-Stable required around 2000u seconds using gcc-2.8.2 on my system. :Setiathome, which is running at a nice of 19, still consumed 90% of :the cpu. A buildworld on 4.0-Stable required 3500u seconds using :gcc-2.95.2 and setiathome didn't accrue any appreciable cpu time :during the build. There were definitely some changes there :). : :Kent : :-- :Kent Stewart :Richland, WA Both 3.4 and 4.0 buildworlds are cpu-bound. If you are trying to test buildworlds, then don't run setiathome (or anything else) while doing the test... it will skew the results of your tests due to differences between the 3.4 and 4.x schedulers (specifically, various scheduler bugs were fixed in 4.x that effect niced cpu-bound background programs such as setiathome, giving them way, way too much cpu). It is simply impossible to fairly measure I/O performance in the presence of unrelated background-running programs, especially under 3.x. And even though 4.x does a better job of it, it will still skew the results. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message