From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762157AbZEGPNk (ORCPT ); Thu, 7 May 2009 11:13:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762024AbZEGPNV (ORCPT ); Thu, 7 May 2009 11:13:21 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:57390 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761451AbZEGPNU (ORCPT ); Thu, 7 May 2009 11:13:20 -0400 Date: Thu, 7 May 2009 16:12:32 +0100 From: Alan Cox To: Christoph Lameter Cc: akataria@vmware.com, "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , the arch/x86 maintainers , LKML Subject: Re: [PATCH] x86: Reduce the default HZ value Message-ID: <20090507161232.6e33df34@lxorguk.ukuu.org.uk> In-Reply-To: References: <1241462661.412.8.camel@alok-dev1> <4A00ADDE.9000908@zytor.com> <20090505224417.0f00c2f0@lxorguk.ukuu.org.uk> <1241561394.8665.31.camel@alok-dev1> <20090505233339.542880f8@lxorguk.ukuu.org.uk> X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 7 May 2009 10:09:56 -0400 (EDT) Christoph Lameter wrote: > On Tue, 5 May 2009, Alan Cox wrote: > > > HZ on a tickless system has no meaningful relationship to wakup rates - > > which are what I assume you actually care about. > > Linux is not tickless. It only switches off ticks if a processor is idle. Hooray - finally someone admits the *real* problem here, and for power management too. Otherwise known as "referencing jiffies as a variable must die" Alan