From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id 7DF02B6FE2 for ; Tue, 20 Dec 2011 04:21:50 +1100 (EST) Message-ID: <4EEF72A8.6010308@redhat.com> Date: Mon, 19 Dec 2011 19:21:44 +0200 From: Avi Kivity MIME-Version: 1.0 To: Alexander Graf Subject: Re: [PATCH v3 12/14] KVM: Add barriers to allow mmu_notifier_retry to be used locklessly References: <20111212222347.GA18868@bloggs.ozlabs.ibm.com> <20111212223720.GM18868@bloggs.ozlabs.ibm.com> <29064998-0526-435B-A8BA-DB6BF9CDED46@suse.de> In-Reply-To: <29064998-0526-435B-A8BA-DB6BF9CDED46@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org, Paul Mackerras , kvm list , kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 12/19/2011 07:18 PM, Alexander Graf wrote: > On 12.12.2011, at 23:37, Paul Mackerras wrote: > > > This adds an smp_wmb in kvm_mmu_notifier_invalidate_range_end() and an > > smp_rmb in mmu_notifier_retry() so that mmu_notifier_retry() will give > > the correct answer when called without kvm->mmu_lock being held. > > PowerPC Book3S HV KVM wants to use a bitlock per guest page rather than > > a single global spinlock in order to improve the scalability of updates > > to the guest MMU hashed page table, and so needs this. > > > > Signed-off-by: Paul Mackerras > > Avi, mind to ack? > Acked-by: Avi Kivity -- error compiling committee.c: too many arguments to function