From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v3 12/14] KVM: Add barriers to allow mmu_notifier_retry to be used locklessly Date: Mon, 19 Dec 2011 19:21:44 +0200 Message-ID: <4EEF72A8.6010308@redhat.com> References: <20111212222347.GA18868@bloggs.ozlabs.ibm.com> <20111212223720.GM18868@bloggs.ozlabs.ibm.com> <29064998-0526-435B-A8BA-DB6BF9CDED46@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Paul Mackerras , linuxppc-dev@ozlabs.org, kvm-ppc@vger.kernel.org, kvm list To: Alexander Graf Return-path: In-Reply-To: <29064998-0526-435B-A8BA-DB6BF9CDED46@suse.de> Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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