Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754777AbXJCOn2 (ORCPT ); Wed, 3 Oct 2007 10:43:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754309AbXJCOnV (ORCPT ); Wed, 3 Oct 2007 10:43:21 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:58988 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753603AbXJCOnV (ORCPT ); Wed, 3 Oct 2007 10:43:21 -0400 Date: Wed, 3 Oct 2007 17:43:19 +0300 (EEST) From: "=?ISO-8859-1?Q?Ilpo_J=E4rvinen?=" X-X-Sender: ijjarvin@kivilampi-30.cs.helsinki.fi To: Frans Pop cc: LKML , "Alexander E. Patrakov" Subject: Re: top displaying 9999% CPU usage In-Reply-To: <200710031604.07365.elendil@planet.nl> Message-ID: References: <200710031433.34504.elendil@planet.nl> <4703932C.6060900@ums.usu.ru> <200710031604.07365.elendil@planet.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1971 Lines: 39 On Wed, 3 Oct 2007, Frans Pop wrote: > On Wednesday 03 October 2007, you wrote: > > Try to capture the i/o log with the following command: > > strace -o top.log top > > Thanks for the suggestion. > > > This will show for sure whether the kernel gives out incorrect data or > > top misinterprets them. > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 5269 fjp 20 0 442m 61m 33m S 9999 3.1 0:34.12 kontact > > Here are the last two reads for PID 5269 from /proc before that: > > 15:48:51 stat("/proc/5269", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 > 15:48:51 open("/proc/5269/stat", O_RDONLY) = 10 > 15:48:51 read(10, "5269 (kontact) S 1 5100 5100 0 -1 4202560 58186 7891 290 1 2911 502 10 15 20 0 6 0 9225 464408576 15694 18446744073709551615 4194304 4365900 140733817144688 18446744073709551615 47998530367074 0 0 4098 83113 18446744073709551615 0 0 17 1 0 0 0\n", 1023) = 244 > 15:48:51 open("/proc/5269/statm", O_RDONLY) = 10 > 15:48:54 stat("/proc/5269", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 > 15:48:54 open("/proc/5269/stat", O_RDONLY) = 10 > 15:48:54 read(10, "5269 (kontact) S 1 5100 5100 0 -1 4202560 58186 7891 290 1 2912 500 10 15 20 0 6 0 9225 464408576 15694 18446744073709551615 4194304 4365900 140733817144688 18446744073709551615 47998530367074 0 0 4098 83113 18446744073709551615 0 0 17 1 0 0 0\n", 1023) = 244 > 15:48:54 open("/proc/5269/statm", O_RDONLY) = 10 > > The only change is in 2 consecutive columns: "2911 502" -> "2912 500". > Is processor usage calculated from those? Can someone explain how? The latter seems to be utime ...decreasing. No wonder if arithmetics will give strange results (probably top is using unsigned delta?)... -- i. - 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/