From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760951AbXK1Wkc (ORCPT ); Wed, 28 Nov 2007 17:40:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757634AbXK1WkY (ORCPT ); Wed, 28 Nov 2007 17:40:24 -0500 Received: from pythia.bakeyournoodle.com ([203.82.209.197]:43941 "EHLO pythia.bakeyournoodle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756579AbXK1WkW (ORCPT ); Wed, 28 Nov 2007 17:40:22 -0500 Date: Thu, 29 Nov 2007 09:40:20 +1100 To: Frederik Himpe Cc: linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net Subject: Re: 2.6.24-rc3-git3: usb hardware interrupts using 25% of CPU time Message-ID: <20071128224020.GE24243@bakeyournoodle.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) From: tony@bakeyournoodle.com (Tony Breeds) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 28, 2007 at 10:33:18PM +0000, Frederik Himpe wrote: > I installed Linux 2.6.24-rc3-git3 on a PPC based Apple Powerbook G4 > system. Now with top I see that over 20% of CPU time is used by hardware > interrupts. Looking at /proc/interrupts, the number in the row > ohci_hcd:usb1 is rising very quickly: Hi Frederik, Thanks for the report. We suspect that this is an accounting problem introduced when powerpc enabled NO_HZ and highres timers. Fortunatley from the testing we've done it doens't actually look like the time is being spent in hardware interupts, just accounted for there. Yours Tony linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/ Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!