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)
> --
> error compiling committee.c: too many arguments to function
>
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