From owner-freebsd-stable@FreeBSD.ORG Wed May 25 22:33:53 2005 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8BE2216A41C for ; Wed, 25 May 2005 22:33:53 +0000 (GMT) (envelope-from jd@ugcs.caltech.edu) Received: from riyal.ugcs.caltech.edu (riyal.ugcs.caltech.edu [131.215.176.123]) by mx1.FreeBSD.org (Postfix) with ESMTP id 551D743D1F for ; Wed, 25 May 2005 22:33:53 +0000 (GMT) (envelope-from jd@ugcs.caltech.edu) Received: by riyal.ugcs.caltech.edu (Postfix, from userid 3640) id A019D45804; Wed, 25 May 2005 15:33:50 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by riyal.ugcs.caltech.edu (Postfix) with ESMTP id DC39245802; Wed, 25 May 2005 15:33:40 -0700 (PDT) Date: Wed, 25 May 2005 15:33:39 -0700 (PDT) From: Jon Dama To: Bjarne Wichmann Petersen In-Reply-To: <200505260014.37054.freebsd.nospam@mekanix.dk> Message-ID: References: <3248.172.16.0.199.1116876092.squirrel@172.16.0.1> <200505252342.01938.freebsd.nospam@mekanix.dk> <20050525214555.GA41695@xor.obsecurity.org> <200505260014.37054.freebsd.nospam@mekanix.dk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Mike Jakubik , Matthias Buelow , freebsd-stable@freebsd.org, Kris Kennaway Subject: Re: Performance of 4.x vs 5.x (Re: Lifetime of FreeBSD branches) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 May 2005 22:33:53 -0000 Could this be quantified by setting up a synthetic experiement: 1) one machine uses dummynet to generate a uniform packet/sec stream 2) another machine has a process receiving those packets and recording their arrival relative to the local TSC. afaik, the TSC is the only source of wall-time that doesn't involve a system call. Is that right? Are the TSCs synchronized on SMP systems? 3) Generate another source of activity on the receiving machine to estimate the effect of PREEMPTION relative to the (lack of) quiescence. 4) use the jitter in the TSC deltas to infer the effect of preemption -Jon On Thu, 26 May 2005, Bjarne Wichmann Petersen wrote: > On Wednesday 25 May 2005 23:45, Kris Kennaway wrote: > > On Wed, May 25, 2005 at 11:42:01PM +0200, Bjarne Wichmann Petersen wrote: > > > I've had PREEMTION enabled in 5-STABLE for at couple of month and had the > > > opposite experience. Eg. when clicking on a file in a fileselector (I'm > > > using KDE) it would take 2-3 seconds before the file got highlighted. > > > After disabling PREEMTION again responsetime seems to have improved. > > Are you running 5.4-RELEASE or later? > > Later (5.4-STABLE). > > Hmm... did a little testing. Sometimes I *still* get "long" responsetimes with > PREEMPTION disabled in a seemingly random order. > > Bjarne > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >