Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933404Ab3GRRV0 (ORCPT ); Thu, 18 Jul 2013 13:21:26 -0400 Received: from mail-vc0-f175.google.com ([209.85.220.175]:60757 "EHLO mail-vc0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932540Ab3GRRVX (ORCPT ); Thu, 18 Jul 2013 13:21:23 -0400 MIME-Version: 1.0 In-Reply-To: References: <1373898101-15633-1-git-send-email-julien.grall@linaro.org> <20130715152532.GC5774@phenom.dumpdata.com> From: Julien Grall Date: Thu, 18 Jul 2013 18:20:52 +0100 Message-ID: Subject: Re: [Xen-devel] [PATCH] xen/arm: disable cpuidle when linux is running as dom0 To: Stefano Stabellini Cc: Konrad Rzeszutek Wilk , Ian Campbell , Patch Tracking , linux-kernel@vger.kernel.org, "xen-devel@lists.xen.org" , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1228 Lines: 33 On 17 July 2013 14:28, Stefano Stabellini wrote: > 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? I have checked with both the Arndale and Versatile Express without any issue. I will resend this patch with disable_cpufreq(). -- Julien Grall -- 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/