From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964826Ab2CMXWv (ORCPT ); Tue, 13 Mar 2012 19:22:51 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:43974 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752051Ab2CMXWr (ORCPT ); Tue, 13 Mar 2012 19:22:47 -0400 From: Konrad Rzeszutek Wilk To: davej@redhat.com, cpufreq@vger.kernel.org, linux-kernel@vger.kernel.org, JBeulich@suse.com Cc: Konrad Rzeszutek Wilk Subject: [PATCH 2/2] xen/cpufreq: Disable the cpu frequency scaling drivers from loading. Date: Tue, 13 Mar 2012 19:18:40 -0400 Message-Id: <1331680720-18268-3-git-send-email-konrad.wilk@oracle.com> X-Mailer: git-send-email 1.7.7.5 In-Reply-To: <1331680720-18268-1-git-send-email-konrad.wilk@oracle.com> References: <1331680720-18268-1-git-send-email-konrad.wilk@oracle.com> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] X-CT-RefId: str=0001.0A020201.4F5FD6C2.00B7,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By using the functionality provided by "[CPUFREQ]: provide disable_cpuidle() function to disable the API." Under the Xen hypervisor we do not want the initial domain to exercise the cpufreq scaling drivers. This is b/c the Xen hypervisor is in charge of doing this as well and we can end up with both the Linux kernel and the hypervisor trying to change the P-states leading to weird performance issues. Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/setup.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index e03c636..4461e0a 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -420,6 +420,7 @@ void __init xen_arch_setup(void) boot_cpu_data.hlt_works_ok = 1; #endif disable_cpuidle(); + disable_cpufreq(); boot_option_idle_override = IDLE_HALT; WARN_ON(set_pm_idle_to_default()); fiddle_vdso(); -- 1.7.9.48.g85da4d