From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933069AbXCELhj (ORCPT ); Mon, 5 Mar 2007 06:37:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933074AbXCELhj (ORCPT ); Mon, 5 Mar 2007 06:37:39 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:48716 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933069AbXCELhi (ORCPT ); Mon, 5 Mar 2007 06:37:38 -0500 Date: Mon, 5 Mar 2007 12:29:28 +0100 From: Ingo Molnar To: Andrew Morton , Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Andi Kleen Subject: [patch] paravirt: allow NO_HZ, remove NO_IDLE_HZ dependency Message-ID: <20070305112928.GA27042@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Subject: [patch] paravirt: remove NO_IDLE_HZ dependency From: Ingo Molnar PARAVIRT forces CONFIG_NO_HZ off - this is bad and prevents sane paravirtual guests like KVM from being able to use dynticks-enabled Linux guests. Remove this. Vmi-timer needs to be updated properly to make use of dynticks. furthermore, remove the mistaken turning on of NO_IDLE_HZ on x86+PARAVIRT kernels, it's an obsolete, limited form of dynticks. must-have for v2.6.21. Signed-off-by: Ingo Molnar --- arch/i386/Kconfig | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) Index: linux/arch/i386/Kconfig =================================================================== --- linux.orig/arch/i386/Kconfig +++ linux/arch/i386/Kconfig @@ -224,7 +224,7 @@ config PARAVIRT config VMI bool "VMI Paravirt-ops support" - depends on PARAVIRT && !NO_HZ + depends on PARAVIRT default y help VMI provides a paravirtualized interface to multiple hypervisors @@ -1291,12 +1291,3 @@ config X86_TRAMPOLINE config KTIME_SCALAR bool default y - -config NO_IDLE_HZ - bool - depends on PARAVIRT - default y - help - Switches the regular HZ timer off when the system is going idle. - This helps a hypervisor detect that the Linux system is idle, - reducing the overhead of idle systems.