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| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2012-07-02 17:56:33 +0900 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-07-18 16:55:04 -0300 |
| commit | b3ae2096974b12c3af2ad1a4e7716b084949867f (patch) | |
| tree | 38ca81ac607cec1c00d6961effb38992577114df | |
| parent | 84504ef38673fa021b3d8f3da2b79cf878b33315 (diff) | |
| download | op-kernel-dev-b3ae2096974b12c3af2ad1a4e7716b084949867f.zip op-kernel-dev-b3ae2096974b12c3af2ad1a4e7716b084949867f.tar.gz | |
KVM: Introduce kvm_unmap_hva_range() for kvm_mmu_notifier_invalidate_range_start()
When we tested KVM under memory pressure, with THP enabled on the host,
we noticed that MMU notifier took a long time to invalidate huge pages.
Since the invalidation was done with mmu_lock held, it not only wasted
the CPU but also made the host harder to respond.
This patch mitigates this by using kvm_handle_hva_range().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 5 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 3 |
5 files changed, 16 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 50ea12f..572ad01 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -52,6 +52,8 @@ struct kvm; extern int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); +extern int kvm_unmap_hva_range(struct kvm *kvm, + unsigned long start, unsigned long end); extern int kvm_age_hva(struct kvm *kvm, unsigned long hva); extern int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); extern void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 1a470bc..3c635c0 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -870,6 +870,13 @@ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) return 0; } +int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) +{ + if (kvm->arch.using_mmu_notifiers) + kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); + return 0; +} + static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, unsigned long gfn) { diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a3e9409..d4aab86 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -944,6 +944,7 @@ extern bool kvm_rebooting; #define KVM_ARCH_WANT_MMU_NOTIFIER int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); +int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end); int kvm_age_hva(struct kvm *kvm, unsigned long hva); int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7235b0c..d2855f8 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1324,6 +1324,11 @@ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp); } +int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) +{ + return kvm_handle_hva_range(kvm, start, end, 0, kvm_unmap_rmapp); +} + void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) { kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b3ce91c..e2b1a15 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -332,8 +332,7 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, * count is also read inside the mmu_lock critical section. */ kvm->mmu_notifier_count++; - for (; start < end; start += PAGE_SIZE) - need_tlb_flush |= kvm_unmap_hva(kvm, start); + need_tlb_flush = kvm_unmap_hva_range(kvm, start, end); need_tlb_flush |= kvm->tlbs_dirty; /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) |
