From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758312AbZEEVXT (ORCPT ); Tue, 5 May 2009 17:23:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752854AbZEEVXK (ORCPT ); Tue, 5 May 2009 17:23:10 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56437 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752491AbZEEVXJ (ORCPT ); Tue, 5 May 2009 17:23:09 -0400 Message-ID: <4A00ADDE.9000908@zytor.com> Date: Tue, 05 May 2009 14:21:34 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: akataria@vmware.com CC: Ingo Molnar , Thomas Gleixner , the arch/x86 maintainers , LKML , alan@lxorguk.ukuu.org.uk Subject: Re: [PATCH] x86: Reduce the default HZ value References: <1241462661.412.8.camel@alok-dev1> In-Reply-To: <1241462661.412.8.camel@alok-dev1> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alok Kataria wrote: > Hi, > > Given that there were no major objections that came up regarding > reducing the HZ value in http://lkml.org/lkml/2009/4/27/499. > > Below is the patch which actually reduces it, please consider for tip. > What is the benefit of this? I can see at least one immediate downside: some timeout values in the kernel are still maintained in units of HZ (like poll, I believe), and so with a lower HZ value we'll have higher roundoff errors. -hpa