Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760853AbXENUmi (ORCPT ); Mon, 14 May 2007 16:42:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758956AbXENUmY (ORCPT ); Mon, 14 May 2007 16:42:24 -0400 Received: from mcr-smtp-001.bulldogdsl.com ([212.158.248.7]:4517 "EHLO mcr-smtp-001.bulldogdsl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758409AbXENUmW (ORCPT ); Mon, 14 May 2007 16:42:22 -0400 X-Spam-Abuse: Please report all spam/abuse matters to abuse@bulldogdsl.com From: Alistair John Strachan To: Jan Engelhardt Subject: Re: [announce] Intel announces the PowerTOP utility for Linux Date: Mon, 14 May 2007 21:42:07 +0100 User-Agent: KMail/1.9.6 Cc: Arjan van de Ven , Linux Kernel Mailing List , linux-acpi@vger.kernel.org References: <4644F726.1050806@linux.intel.com> <200705122212.43653.s0348365@sms.ed.ac.uk> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200705142142.07983.s0348365@sms.ed.ac.uk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1588 Lines: 36 On Monday 14 May 2007 21:22:50 Jan Engelhardt wrote: > On May 12 2007 22:12, Alistair John Strachan wrote: > >On Saturday 12 May 2007 00:07:18 Arjan van de Ven wrote: > >> What's eating the battery life of my laptop? Why isn't it many more > >> hours? Which software component causes the most power to be burned? > >> These are important questions without a good answer... until now. > > > >This is a really great tool and presents a very intuitive alternative to > > the timer stats file.. > > > >On a Core 2 Duo Macbook, Linux always gets around 3.2h battery, OS X about > >4.2h. This tool has identified that uhci_hcd is where 75% of the ticks are > >going when X is not loaded. Unloading uhci_hcd drops the battery life back > > to around 4.2h, but I lose the keyboard. > > > >Is there any way to find out what USB driver is causing usb_uhci to be > > this busy? > > At its worst, it _is_ the USB chip that draws the power when it is active > (when uhci_hcd is loaded); does not need to be usbhid or so. This is certainly true, and to a significant extent it _was_ the uhci_hcd, but it turns out the main contributor to HZ here were the appletouch and hci_usb drivers. Disabling both drops the ticks down from about 850 to 150. -- Cheers, Alistair. Final year Computer Science undergraduate. 1F2 55 South Clerk Street, Edinburgh, UK. - 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/