Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 8 Oct 2002 14:58:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 8 Oct 2002 14:57:33 -0400 Received: from tmr-02.dsl.thebiz.net ([216.238.38.204]:17164 "EHLO gatekeeper.tmr.com") by vger.kernel.org with ESMTP id ; Tue, 8 Oct 2002 14:57:25 -0400 Date: Tue, 8 Oct 2002 14:55:01 -0400 (EDT) From: Bill Davidsen To: Larry McVoy cc: "David S. Miller" , mau@oscar.prima.de, linux-kernel@vger.kernel.org Subject: Re: LMbench results for 2.5.40 In-Reply-To: <20021001163757.J13270@work.bitmover.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1143 Lines: 28 On Tue, 1 Oct 2002, Larry McVoy wrote: > By the way, the place you will probably see variance in LMbench is in the > context switch benchmarks, it's almost certainly due to randomness in > cache layout and there isn't a thing we can do about it. You can run a > zillion runs to get an average but please realize that is an *average*. > The context switch number are accurate, the low ones represent no cache > collisions and the high ones represent lots of cache collisions. > > FYI. I don't like it either. Thank you, that explains some things I've seen in my context switching benchmark as well, which uses a bunch of different services to transfer tiny data from on process to another. Time for some statistical jiggery-pokery, dust off deviant mean or some such. -- bill davidsen CTO, TMR Associates, Inc Doing interesting things with little computers since 1979. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/