From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2] KVM: MMU: optimize pte write path if don't have protected sp Date: Wed, 11 May 2011 14:28:03 +0300 Message-ID: <4DCA72C3.6050300@redhat.com> References: <4DC9F803.3050602@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM To: Xiao Guangrong Return-path: In-Reply-To: <4DC9F803.3050602@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/11/2011 05:44 AM, Xiao Guangrong wrote: > Simply return from kvm_mmu_pte_write path if no shadow page is > write-protected, then we can avoid to walk all shadow pages and hold > mmu-lock > > @@ -1038,8 +1038,10 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) > hlist_del(&sp->hash_link); > list_del(&sp->link); > free_page((unsigned long)sp->spt); > - if (!sp->role.direct) > + if (!sp->role.direct) { > free_page((unsigned long)sp->gfns); > + atomic_dec(&kvm->arch.indirect_shadow_pages); > + } > kmem_cache_free(mmu_page_header_cache, sp); > kvm_mod_used_mmu_pages(kvm, -1); > } > @@ -1536,6 +1538,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > kvm_sync_pages(vcpu, gfn); > > account_shadowed(vcpu->kvm, gfn); > + atomic_inc(&vcpu->kvm->arch.indirect_shadow_pages); > } Better in account_shadowed()/unaccount_shadowed(), no? -- error compiling committee.c: too many arguments to function