From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751917AbZJEFDy (ORCPT ); Mon, 5 Oct 2009 01:03:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751109AbZJEFDx (ORCPT ); Mon, 5 Oct 2009 01:03:53 -0400 Received: from mail-px0-f179.google.com ([209.85.216.179]:50046 "EHLO mail-px0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbZJEFDx (ORCPT ); Mon, 5 Oct 2009 01:03:53 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Sun, 4 Oct 2009 22:03:16 -0700 Message-ID: Subject: Re: cpufreq scaling strangely, system feels warm From: Steven Noonan To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 4, 2009 at 7:24 PM, Steven Noonan wrote: > On Sat, Oct 3, 2009 at 5:54 PM, Steven Noonan wrote: >> I have a system that's behaving as though it's under a moderate load, >> but nothing's happening and the load average is zero. If I change my >> cpufreq governor to 'conservative' or 'ondemand', the CPU immediately >> scales up to the maximum clock frequency (as though something was >> demanding that much power). The system is also very warm, which is >> abnormal even when the machine is always clocked at its maximum >> frequency. >> >> Top shows that there are no processes which are hogging the CPU, and >> /proc/interrupts doesn't reveal anything interesting (i.e. an >> interrupt storm). The only way to get my system to stay cool is to >> change the cpufreq governor to 'powersave' or 'userspace' (and then >> clock it at the lowest, manually). >> > > Scratch that. It's probably an interrupt storm. 'perf top' shows > 19,000 IRQs per second. And I recall that 500-1500 per second was > normal for this machine. Now the problem is figuring out where the > interrupt storm is coming from... > Went through my kernel config and found some odd settings, fixed them and recompiled. Now 'ondemand' works as it should, but 'conservative' always clocks up to the maximum frequency. I can't figure out why. Is there a way to get cpufreq to print out some explanations in dmesg as to why 'conservative' is doing what it does? - Steven