Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756630Ab3DZQUa (ORCPT ); Fri, 26 Apr 2013 12:20:30 -0400 Received: from smtp.citrix.com ([66.165.176.89]:51920 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751909Ab3DZQU3 (ORCPT ); Fri, 26 Apr 2013 12:20:29 -0400 X-IronPort-AV: E=Sophos;i="4.87,559,1363132800"; d="scan'208";a="21837090" Date: Fri, 26 Apr 2013 17:20:23 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: Stefano Stabellini , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" Subject: Re: [PATCH 7/9] xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM In-Reply-To: <1366142947-18655-8-git-send-email-konrad.wilk@oracle.com> Message-ID: References: <1366142947-18655-1-git-send-email-konrad.wilk@oracle.com> <1366142947-18655-8-git-send-email-konrad.wilk@oracle.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: 2255 Lines: 70 On Tue, 16 Apr 2013, Konrad Rzeszutek Wilk wrote: > See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 > (xen: disable PV spinlocks on HVM) for details. > > But we did not disable it everywhere - which means that when > we boot as PVHVM we end up allocating per-CPU irq line for > spinlock. This fixes that. > > Signed-off-by: Konrad Rzeszutek Wilk Is there any point in calling xen_init_lock_cpu in PVHVM guests? At that point we might as well remove the call from xen_hvm_cpu_notify. > arch/x86/xen/spinlock.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c > index 47ae032..8b54603 100644 > --- a/arch/x86/xen/spinlock.c > +++ b/arch/x86/xen/spinlock.c > @@ -367,6 +367,13 @@ void __cpuinit xen_init_lock_cpu(int cpu) > WARN(per_cpu(lock_kicker_irq, cpu) > 0, "spinlock on CPU%d exists on IRQ%d!\n", > cpu, per_cpu(lock_kicker_irq, cpu)); > > + /* > + * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 > + * (xen: disable PV spinlocks on HVM) > + */ > + if (xen_hvm_domain()) > + return; > + > name = kasprintf(GFP_KERNEL, "spinlock%d", cpu); > irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR, > cpu, > @@ -385,12 +392,26 @@ void __cpuinit xen_init_lock_cpu(int cpu) > > void xen_uninit_lock_cpu(int cpu) > { > + /* > + * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 > + * (xen: disable PV spinlocks on HVM) > + */ > + if (xen_hvm_domain()) > + return; > + > unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL); > per_cpu(lock_kicker_irq, cpu) = -1; > } > > void __init xen_init_spinlocks(void) > { > + /* > + * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 > + * (xen: disable PV spinlocks on HVM) > + */ > + if (xen_hvm_domain()) > + return; > + > BUILD_BUG_ON(sizeof(struct xen_spinlock) > sizeof(arch_spinlock_t)); > > pv_lock_ops.spin_is_locked = xen_spin_is_locked; > -- > 1.8.1.4 > -- 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/