From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757089Ab1IGVYf (ORCPT ); Wed, 7 Sep 2011 17:24:35 -0400 Received: from claw.goop.org ([74.207.240.146]:53566 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757027Ab1IGVYe (ORCPT ); Wed, 7 Sep 2011 17:24:34 -0400 Message-ID: <4E67E10A.3020809@goop.org> Date: Wed, 07 Sep 2011 14:24:26 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110816 Thunderbird/6.0 MIME-Version: 1.0 To: stefano.stabellini@eu.citrix.com CC: konrad.wilk@oracle.com, linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com Subject: Re: [PATCH] xen: disable PV spinlocks on HVM References: <1315327307-392-1-git-send-email-stefano.stabellini@eu.citrix.com> In-Reply-To: <1315327307-392-1-git-send-email-stefano.stabellini@eu.citrix.com> X-Enigmail-Version: 1.3.1 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/06/2011 09:41 AM, stefano.stabellini@eu.citrix.com wrote: > From: Stefano Stabellini > > PV spinlocks cannot possibly work with the current code because they are > enabled after pvops patching has already been done, and because PV > spinlocks use a different data structure than native spinlocks so we > cannot switch between them dynamically. A spinlock that has been taken > once by the native code (__ticket_spin_lock) cannot be taken by > __xen_spin_lock even after it has been released. > > Reported-by: Stefan Bader > Signed-off-by: Stefano Stabellini > --- > arch/x86/xen/smp.c | 1 - > 1 files changed, 0 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c > index e79dbb9..51339b4 100644 > --- a/arch/x86/xen/smp.c > +++ b/arch/x86/xen/smp.c > @@ -522,7 +522,6 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) > WARN_ON(xen_smp_intr_init(0)); > > xen_init_lock_cpu(0); > - xen_init_spinlocks(); > } Should I add this back here on the pv ticketlock branch? J