On 05/15/2011 12:35 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 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 2841805..971e2d2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -498,6 +498,7 @@ static void account_shadowed(struct kvm *kvm, gfn_t gfn) linfo = lpage_info_slot(gfn, slot, i); linfo->write_count += 1; } + atomic_inc(&kvm->arch.indirect_shadow_pages); } static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) @@ -513,6 +514,7 @@ static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) linfo->write_count -= 1; WARN_ON(linfo->write_count< 0); } + atomic_dec(&kvm->arch.indirect_shadow_pages); }
These atomic ops are always called from within the spinlock, so we don't need an atomic_t here.
Sorry, I should have noticed this on the first version. -- error compiling committee.c: too many arguments to function -- 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
