From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Bader Subject: Re: [Xen-devel] [PATCH] xen: disable PV spinlocks on HVM Date: Tue, 06 Sep 2011 10:18:08 -0700 Message-ID: <4E6655D0.2080606@canonical.com> References: <1315327307-392-1-git-send-email-stefano.stabellini@eu.citrix.com> <20110906170255.GA29839@dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110906170255.GA29839@dumpdata.com> Sender: linux-kernel-owner@vger.kernel.org To: Konrad Rzeszutek Wilk Cc: stefano.stabellini@eu.citrix.com, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org List-Id: xen-devel@lists.xenproject.org On 06.09.2011 10:02, Konrad Rzeszutek Wilk wrote: > On Tue, Sep 06, 2011 at 05:41:47PM +0100, 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. > > Let me stick it on my 3.1-rc5 bug-fix list and add stable@kernel.org to it. > > Stefan, if you have some time this week, and can test it - I can also > stick 'Tested-by' if you would like. > > Thinking to send the patches on Friday. > >> >> 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(); >> } >> >> static int __cpuinit xen_hvm_cpu_up(unsigned int cpu) >> -- >> 1.7.2.3 >> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xensource.com >> http://lists.xensource.com/xen-devel I'll try. Currently I only got a version tested that takes out the xen_init_lock_cpu calls as well. -Stefan