Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754682Ab0HXJuZ (ORCPT ); Tue, 24 Aug 2010 05:50:25 -0400 Received: from mail-qy0-f174.google.com ([209.85.216.174]:33481 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754188Ab0HXJuW convert rfc822-to-8bit (ORCPT ); Tue, 24 Aug 2010 05:50:22 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=nosx+q65KHi1va44KWoCOEv3gD7WlD1eHpRiNCcPmvcUlBTWMpoZr90oqFCPep7qBt QB2xVdMVQt1T6OjsYYgDAwvA7ntgg3ifdl/QQDdQ9JhpdfYy6RJ9DVFarDOEUXzke711 Ojk4/ozUD49ZLw1bQ5+j5wjB837I2POe64rPs= MIME-Version: 1.0 In-Reply-To: <20100824020721.GA14726@amt.cnet> References: <20100820011054.GA11297@tpepper-t61p.dolavim.us> <4C724BDB.8020604@redhat.com> <4C724D13.6000807@redhat.com> <20100824020721.GA14726@amt.cnet> Date: Tue, 24 Aug 2010 17:50:20 +0800 Message-ID: Subject: Re: [PATCH 0/4 v2] kvm: rework KVM mmu_shrink() code From: Xiaotian Feng To: Marcelo Tosatti Cc: Avi Kivity , Tim Pepper , Lai Jiangshan , Dave Hansen , LKML , kvm@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3146 Lines: 72 On Tue, Aug 24, 2010 at 10:07 AM, Marcelo Tosatti wrote: > On Mon, Aug 23, 2010 at 07:11:11PM +0800, Xiaotian Feng wrote: >> On Mon, Aug 23, 2010 at 6:27 PM, Avi Kivity wrote: >> >  On 08/23/2010 01:22 PM, Avi Kivity wrote: >> >> >> >> >> >> I see a lot of soft lockups with this patchset: >> > >> > This is running the emulator.flat test case, with shadow paging.  This test >> > triggers a lot (millions) of mmu mode switches. >> > >> >> Does following patch fix your issue? >> >> Latest kvm mmu_shrink code rework makes kernel changes >> kvm->arch.n_used_mmu_pages/ >> kvm->arch.n_max_mmu_pages at kvm_mmu_free_page/kvm_mmu_alloc_page, >> which is called >> by kvm_mmu_commit_zap_page. So the kvm->arch.n_used_mmu_pages or >> kvm_mmu_available_pages(vcpu->kvm) is unchanged after kvm_mmu_commit_zap_page(), >> This caused kvm_mmu_change_mmu_pages/__kvm_mmu_free_some_pages looping forever. >> Moving kvm_mmu_commit_zap_page would make the while loop performs as normal. >> >> --- >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index f52a965..7e09a21 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -1726,8 +1726,8 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, >> unsigned int goal_nr_mmu_pages) >>                                             struct kvm_mmu_page, link); >>                         kvm_mmu_prepare_zap_page(kvm, page, >>                                                                &invalid_list); >> +                       kvm_mmu_commit_zap_page(kvm, &invalid_list); >>                 } >> -               kvm_mmu_commit_zap_page(kvm, &invalid_list); >>                 goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages; >>         } >> >> @@ -2976,9 +2976,9 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) >>                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev, >>                                   struct kvm_mmu_page, link); >>                 kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); >> +               kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); >>                 ++vcpu->kvm->stat.mmu_recycled; >>         } >> -       kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); >>  } >> >>  int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) > > Please resend with a signed-off-by, and proper subject for the patch. It's available at: https://patchwork.kernel.org/patch/125431/ Thanks Xiaotian > > Thanks > > -- > 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/ > -- 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/