From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 31 Mar 2001 00:45:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 31 Mar 2001 00:45:42 -0500 Received: from supreme.pcug.org.au ([203.10.76.34]:4039 "EHLO pcug.org.au") by vger.kernel.org with ESMTP id ; Sat, 31 Mar 2001 00:45:29 -0500 Message-Id: <200103310544.f2V5icO07172@pcug.org.au> From: Stephen Rothwell To: Jamie Lokier cc: linux-kernel@vger.kernel.org Subject: Re: kapm-idled using 45% CPU (why not 100%?) In-Reply-To: Your message of Sat, 31 Mar 2001 03:35:04 +0200. <20010331033504.A7022@pcep-jamie.cern.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2409.986017478.1@rustcorp.com.au> Date: Sat, 31 Mar 2001 15:44:38 +1000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Jamie, Jamie Lokier writes: > Subject says it all. On my laptop which is running 2.4.0, while the > machine is completely idle "top" reports kapm-idled as usin about 45% of > the CPU. The remaining 55% is reported as idle time. This is normal behaviour ... the current implementation of kapm-idled means that it is sleeping some of the time, so the real idle process actually gets some time. I did a patch a while ago the got the kapm-idled up to about 93-95%, but I didn;t think i was all that important. > When the machine gets a little more active, the CPU time attributed to > kapm-idled decreases while the 55% idle time increases to 85%! Again this is normal (although it may not seem sensible). > This is not caused be "top": I get the same 45% from "ps -l 3". > > I remember when kapmd was reporting 100%. Is the new behaviour > intentional, and is it saving the maximum power on the laptop? I have NEVER seen kapmd getting 100%. You are probably getting about as good power saving as you will get (unfortunately) although don't hold me to that - I have heard of some laptops that get better power savings when CONFIG_APM_CPU_IDLE was NOT set ... Cheers, Stephen