On Tue, Aug 24, 2010 at 10:07 AM, Marcelo Tosatti <mtosatti@xxxxxxxxxx> 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 <avi@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx > 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 kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
