[PATCH v4 8/9] KVM MMU: no need atomic operation for 'invlpg_counter'
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From: Xiao Guangrong on 6 May 2010 05:40 'invlpg_counter' is protected by 'kvm->mmu_lock', no need atomic operation anymore Signed-off-by: Xiao Guangrong <xiaoguangrong(a)cn.fujitsu.com> --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/paging_tmpl.h | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 86a8550..f4e8973 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -387,7 +387,7 @@ struct kvm_arch { unsigned int n_free_mmu_pages; unsigned int n_requested_mmu_pages; unsigned int n_alloc_mmu_pages; - atomic_t invlpg_counter; + unsigned int invlpg_counter; struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES]; /* * Hash table of struct kvm_mmu_page. diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 93ee2d9..ceaac55 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -466,7 +466,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) struct kvm_shadow_walk_iterator iterator; gfn_t gfn = -1; u64 *sptep = NULL, gentry; - int invlpg_counter, level, offset = 0, need_flush = 0; + unsigned int invlpg_counter; + int level, offset = 0, need_flush = 0; spin_lock(&vcpu->kvm->mmu_lock); @@ -502,7 +503,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) if (need_flush) kvm_flush_remote_tlbs(vcpu->kvm); - invlpg_counter = atomic_add_return(1, &vcpu->kvm->arch.invlpg_counter); + invlpg_counter = ++vcpu->kvm->arch.invlpg_counter; spin_unlock(&vcpu->kvm->mmu_lock); if (gfn == -1) @@ -522,7 +523,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) kvm_mmu_free_page(vcpu->kvm, sp); goto unlock_exit; } - if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter && + if (vcpu->kvm->arch.invlpg_counter == invlpg_counter && sp->role.level == PT_PAGE_TABLE_LEVEL) { ++vcpu->kvm->stat.mmu_pte_updated; FNAME(update_pte)(vcpu, sp, sptep, &gentry); -- 1.6.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |