Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765115AbXHFNsL (ORCPT ); Mon, 6 Aug 2007 09:48:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761539AbXHFNr4 (ORCPT ); Mon, 6 Aug 2007 09:47:56 -0400 Received: from mx1.redhat.com ([66.187.233.31]:33494 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761706AbXHFNrz (ORCPT ); Mon, 6 Aug 2007 09:47:55 -0400 Message-ID: <46B72688.8070303@redhat.com> Date: Mon, 06 Aug 2007 09:47:52 -0400 From: Chris Snook User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Jan Engelhardt CC: Linux Kernel Mailing List Subject: Re: Few interrupts with NO_HZ References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 974 Lines: 30 Jan Engelhardt wrote: > Hi, > > > this more of an informational question. So: > > kernel version is 2.6.22.1 on i686 > > /proc/uptime > 9917.81 9140.90 (2h45m) > > /proc/cpuinfo: > CPU0 > 0: 282 IO-APIC-edge timer > > this is kinda neat, I expected much more interrupts than just 282 since > boot. What kernel code actually uses the irq0 timer? If you don't have an HPET (and most single-processor systems do not) the kernel is probably using the PIT to wake the processor from low-power sleep states, since the LAPIC timer is disabled in these states. If your box is mostly idle, you might want to use powertop to figure out why it's entering low power states so infrequently. -- Chris - 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/