From owner-freebsd-current@FreeBSD.ORG Tue Feb 22 20:26:51 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1CFB0106566B for ; Tue, 22 Feb 2011 20:26:50 +0000 (UTC) (envelope-from jmg@h2.funkthat.com) Received: from h2.funkthat.com (gate.funkthat.com [70.36.235.232]) by mx1.freebsd.org (Postfix) with ESMTP id DD81D8FC1D for ; Tue, 22 Feb 2011 20:26:49 +0000 (UTC) Received: from h2.funkthat.com (localhost [127.0.0.1]) by h2.funkthat.com (8.14.3/8.14.3) with ESMTP id p1MJvERg073860 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 22 Feb 2011 11:57:14 -0800 (PST) (envelope-from jmg@h2.funkthat.com) Received: (from jmg@localhost) by h2.funkthat.com (8.14.3/8.14.3/Submit) id p1MJvEWT073859; Tue, 22 Feb 2011 11:57:14 -0800 (PST) (envelope-from jmg) Date: Tue, 22 Feb 2011 11:57:13 -0800 From: John-Mark Gurney To: Jerome Flesch Message-ID: <20110222195713.GW66284@funkthat.com> Mail-Followup-To: Jerome Flesch , Chuck Swiger , freebsd-current@freebsd.org References: <4D6291A5.4050206@netasq.com> <8C8FE4A5-F031-466A-9CB8-46D79EEA280D@mac.com> <4D638050.2010906@netasq.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D638050.2010906@netasq.com> User-Agent: Mutt/1.4.2.3i X-Operating-System: FreeBSD 7.2-RELEASE i386 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.2 (h2.funkthat.com [127.0.0.1]); Tue, 22 Feb 2011 11:57:14 -0800 (PST) X-Mailman-Approved-At: Tue, 22 Feb 2011 20:37:17 +0000 Cc: freebsd-current@freebsd.org Subject: Re: Process timing issue X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2011 20:26:51 -0000 Jerome Flesch wrote this message on Tue, Feb 22, 2011 at 10:22 +0100: > We expected both processes (the test program and openssl) to have each > half the CPU time and being scheduled quite often (at least once each > 10ms). According to the output of our test program, it works fine for > most of the calls to clock_gettime(), but from time to time (about 1 > loop in 200000 on my computer), we have a latency pike (>= 100ms). Are you sure there isn't a cron task or something else that is suddenly waking up, causing a large CPU spike? -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."