Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755367Ab3GQN24 (ORCPT ); Wed, 17 Jul 2013 09:28:56 -0400 Received: from smtp.citrix.com ([66.165.176.89]:63741 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753892Ab3GQN2z (ORCPT ); Wed, 17 Jul 2013 09:28:55 -0400 X-IronPort-AV: E=Sophos;i="4.89,684,1367971200"; d="scan'208";a="37503721" Date: Wed, 17 Jul 2013 14:28:43 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: Julien Grall , , , , , , Subject: Re: [Xen-devel] [PATCH] xen/arm: disable cpuidle when linux is running as dom0 In-Reply-To: <20130715152532.GC5774@phenom.dumpdata.com> Message-ID: References: <1373898101-15633-1-git-send-email-julien.grall@linaro.org> <20130715152532.GC5774@phenom.dumpdata.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1996 Lines: 67 On Mon, 15 Jul 2013, Konrad Rzeszutek Wilk wrote: > On Mon, Jul 15, 2013 at 03:21:41PM +0100, Julien Grall wrote: > > When linux is running as dom0, Xen doesn't show the physical cpu but a > > virtual CPU. > > On some ARM SOC (for instance the exynos 5250), linux registers callbacks > > for cpuidle. When these callbacks are called, they will modify > > directly the physical cpu not the virtual one. > It can impact the whole board > > instead of dom0. Certainly this is something that should be fixed at the hypervisor level too. However I agree that Linux should try to avoid doing that when running on Xen. > Should you also call disable_cpufreq() ? Sounds like a good idea. Julien, could you add that to this patch? > > > > Signed-off-by: Julien Grall > > --- > > arch/arm/xen/enlighten.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > > index 49839d8..a98999f 100644 > > --- a/arch/arm/xen/enlighten.c > > +++ b/arch/arm/xen/enlighten.c > > @@ -24,6 +24,8 @@ > > #include > > #include > > #include > > +#include > > +#include > > > > #include > > > > @@ -292,6 +294,11 @@ static int __init xen_pm_init(void) > > { > > pm_power_off = xen_power_off; > > arm_pm_restart = xen_restart; > > + /* > > + * Making sure board specific code will not set up ops for > > + * cpu idle. > > + */ > > + disable_cpuidle(); > > > > return 0; > > } > > -- > > 1.7.10.4 > > > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xen.org > > http://lists.xen.org/xen-devel > -- 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/