From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 12 Apr 2001 12:08:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 12 Apr 2001 12:08:34 -0400 Received: from [212.199.50.10] ([212.199.50.10]:26563 "EHLO specialk.benyossef.com") by vger.kernel.org with ESMTP id ; Thu, 12 Apr 2001 12:08:17 -0400 Message-ID: <3AD5C626.2050507@benyossef.com> Date: Thu, 12 Apr 2001 18:13:42 +0300 From: Gilad Ben-Yossef Organization: Great Illuminated Seers of Bavaria User-Agent: Mozilla/5.0 (X11; U; Linux 2.2.12-20 i686; en-US; m18) Gecko/20001107 Netscape6/6.0 X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: cpu load calculation Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi there, We think we might have encountered a problem with the cpu load calculation in Linux (2.2.x). The current calculation is based on dividing the jiffies to user, system and idle jiffies according to the process the timer hardware interrupt interrupts. In our case the timer interrupt generates some kernel processing in the bottom half. After that finishes, the idle process takes over. The system therefore seems completely idle while in actuality if the kernel processing takes 50% of a jiffie the system is 50% loaded (with system processing). The problem obviously results from synchronization of processing with the timer interrupt used to calculate the load. - Did anybody encounter this problem? - Know any solutions? - Recommend any specific solution? Many thanks, Gilad. -- Gilad Ben-Yossef http://benyossef.com :: +972(54)756701 "Anything that can go wrong, will go wrong, while interrupts are disabled. " -- Murphey's law of kernel programing.