Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263173AbUA0RbG (ORCPT ); Tue, 27 Jan 2004 12:31:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264889AbUA0RbG (ORCPT ); Tue, 27 Jan 2004 12:31:06 -0500 Received: from elektroni.ee.tut.fi ([130.230.131.11]:45698 "HELO elektroni.ee.tut.fi") by vger.kernel.org with SMTP id S263173AbUA0RbE (ORCPT ); Tue, 27 Jan 2004 12:31:04 -0500 Date: Tue, 27 Jan 2004 19:31:02 +0200 From: Petri Kaukasoina To: linux-kernel@vger.kernel.org Subject: Re: 2.6.1: process start times by procps Message-ID: <20040127173102.GA15052@elektroni.ee.tut.fi> Mail-Followup-To: linux-kernel@vger.kernel.org References: <20040123194714.GA22315@elektroni.ee.tut.fi> <20040125110847.GA10824@elektroni.ee.tut.fi> <20040127155254.GA1656@elektroni.ee.tut.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040127155254.GA1656@elektroni.ee.tut.fi> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1588 Lines: 32 On Tue, Jan 27, 2004 at 05:52:54PM +0200, Petri Kaukasoina wrote: > I made an experiment shown below. I know nothing about kernel programming, > so this is probably not correct, but at least btime seemed to stay constant. > (I don't believe this fixes procps, though. If HZ if off by 180 ppm then I > guess ps can't possibly get its calculations involving HZ right. But at > least the bootup time reported by procinfo stays constant.) Yes, btime stays now constant. But to make ps work right, I replaced all uses of variable Hertz in ps source (procps 2.0.18) with constant 100.0172. After uptime 4 h 42 min, the error is already 3 seconds in the default ps, and ./ps which is the "fixed" one, displays the right start time. Tue Jan 27 19:17:57 EET 2004 kaukasoi 13388 0.0 0.1 2652 740 pts/5 R 19:17 0:00 ps uxw kaukasoi 13392 0.0 0.1 2636 724 pts/5 R 19:17 0:00 ./ps uxw Tue Jan 27 19:17:57 EET 2004 kaukasoi 13398 0.0 0.1 2652 740 pts/5 R 19:18 0:00 ps uxw kaukasoi 13402 0.0 0.1 2636 724 pts/5 R 19:17 0:00 ./ps uxw Tue Jan 27 19:17:57 EET 2004 ... Tue Jan 27 19:17:59 EET 2004 kaukasoi 13979 0.0 0.1 2652 740 pts/5 R 19:18 0:00 ps uxw kaukasoi 13983 0.0 0.1 2636 724 pts/5 R 19:18 0:00 ./ps uxw Tue Jan 27 19:18:00 EET 2004 So the problem is the inaccuracy of HZ. - 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/