---

yaml --- r: 230799 b: refs/heads/master c: 8ee5382 h: refs/heads/master i: 230797: 43a196b 230795: ba8c3eb 230791: d0b0327 230783: 0bb77c6 v: v3
git-mirror · Jan 14, 2011 · 566a5d3 · 566a5d3
1 parent e47f35b
commit 566a5d3
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Showing 8 changed files with 106 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4b7167b9ff9b7f3f528cbc4c7d02ebd275b9b10c
+refs/heads/master: 8ee53820edfd1f3b6554c593f337148dd3d7fc91
diff --git a/trunk/arch/x86/include/asm/kvm_host.h b/trunk/arch/x86/include/asm/kvm_host.h
@@ -822,6 +822,7 @@ extern bool kvm_rebooting;
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
 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);
 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);

diff --git a/trunk/arch/x86/kvm/mmu.c b/trunk/arch/x86/kvm/mmu.c
@@ -945,6 +945,35 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 	return young;
 }
 
+static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
+			      unsigned long data)
+{
+	u64 *spte;
+	int young = 0;
+
+	/*
+	 * If there's no access bit in the secondary pte set by the
+	 * hardware it's up to gup-fast/gup to set the access bit in
+	 * the primary pte or in the page structure.
+	 */
+	if (!shadow_accessed_mask)
+		goto out;
+
+	spte = rmap_next(kvm, rmapp, NULL);
+	while (spte) {
+		u64 _spte = *spte;
+		BUG_ON(!(_spte & PT_PRESENT_MASK));
+		young = _spte & PT_ACCESSED_MASK;
+		if (young) {
+			young = 1;
+			break;
+		}
+		spte = rmap_next(kvm, rmapp, spte);
+	}
+out:
+	return young;
+}
+
 #define RMAP_RECYCLE_THRESHOLD 1000
 
 static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
@@ -965,6 +994,11 @@ int kvm_age_hva(struct kvm *kvm, unsigned long hva)
 	return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
 }
 
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
+{
+	return kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp);
+}
+
 #ifdef MMU_DEBUG
 static int is_empty_shadow_page(u64 *spt)
 {

diff --git a/trunk/arch/x86/mm/gup.c b/trunk/arch/x86/mm/gup.c
@@ -8,6 +8,7 @@
 #include <linux/mm.h>
 #include <linux/vmstat.h>
 #include <linux/highmem.h>
+#include <linux/swap.h>
 
 #include <asm/pgtable.h>
 
@@ -89,6 +90,7 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
 		VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
 		page = pte_page(pte);
 		get_page(page);
+		SetPageReferenced(page);
 		pages[*nr] = page;
 		(*nr)++;
 
@@ -103,6 +105,7 @@ static inline void get_head_page_multiple(struct page *page, int nr)
 	VM_BUG_ON(page != compound_head(page));
 	VM_BUG_ON(page_count(page) == 0);
 	atomic_add(nr, &page->_count);
+	SetPageReferenced(page);
 }
 
 static inline void get_huge_page_tail(struct page *page)

diff --git a/trunk/include/linux/mmu_notifier.h b/trunk/include/linux/mmu_notifier.h
@@ -61,6 +61,16 @@ struct mmu_notifier_ops {
 				 struct mm_struct *mm,
 				 unsigned long address);
 
+	/*
+	 * test_young is called to check the young/accessed bitflag in
+	 * the secondary pte. This is used to know if the page is
+	 * frequently used without actually clearing the flag or tearing
+	 * down the secondary mapping on the page.
+	 */
+	int (*test_young)(struct mmu_notifier *mn,
+			  struct mm_struct *mm,
+			  unsigned long address);
+
 	/*
 	 * change_pte is called in cases that pte mapping to page is changed:
 	 * for example, when ksm remaps pte to point to a new shared page.
@@ -163,6 +173,8 @@ extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
 extern void __mmu_notifier_release(struct mm_struct *mm);
 extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 					  unsigned long address);
+extern int __mmu_notifier_test_young(struct mm_struct *mm,
+				     unsigned long address);
 extern void __mmu_notifier_change_pte(struct mm_struct *mm,
 				      unsigned long address, pte_t pte);
 extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
@@ -186,6 +198,14 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
 	return 0;
 }
 
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	if (mm_has_notifiers(mm))
+		return __mmu_notifier_test_young(mm, address);
+	return 0;
+}
+
 static inline void mmu_notifier_change_pte(struct mm_struct *mm,
 					   unsigned long address, pte_t pte)
 {
@@ -313,6 +333,12 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
 	return 0;
 }
 
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	return 0;
+}
+
 static inline void mmu_notifier_change_pte(struct mm_struct *mm,
 					   unsigned long address, pte_t pte)
 {

diff --git a/trunk/mm/huge_memory.c b/trunk/mm/huge_memory.c
@@ -1632,7 +1632,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 		VM_BUG_ON(PageLRU(page));
 
 		/* If there is no mapped pte young don't collapse the page */
-		if (pte_young(pteval))
+		if (pte_young(pteval) || PageReferenced(page) ||
+		    mmu_notifier_test_young(vma->vm_mm, address))
 			referenced = 1;
 	}
 	if (unlikely(!referenced))
@@ -1892,7 +1893,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 		/* cannot use mapcount: can't collapse if there's a gup pin */
 		if (page_count(page) != 1)
 			goto out_unmap;
-		if (pte_young(pteval))
+		if (pte_young(pteval) || PageReferenced(page) ||
+		    mmu_notifier_test_young(vma->vm_mm, address))
 			referenced = 1;
 	}
 	if (referenced)

diff --git a/trunk/mm/mmu_notifier.c b/trunk/mm/mmu_notifier.c
@@ -100,6 +100,26 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 	return young;
 }
 
+int __mmu_notifier_test_young(struct mm_struct *mm,
+			      unsigned long address)
+{
+	struct mmu_notifier *mn;
+	struct hlist_node *n;
+	int young = 0;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) {
+		if (mn->ops->test_young) {
+			young = mn->ops->test_young(mn, mm, address);
+			if (young)
+				break;
+		}
+	}
+	rcu_read_unlock();
+
+	return young;
+}
+
 void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
 			       pte_t pte)
 {

diff --git a/trunk/virt/kvm/kvm_main.c b/trunk/virt/kvm/kvm_main.c
@@ -380,6 +380,22 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
 	return young;
 }
 
+static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
+				       struct mm_struct *mm,
+				       unsigned long address)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int young, idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	young = kvm_test_age_hva(kvm, address);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	return young;
+}
+
 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
 				     struct mm_struct *mm)
 {
@@ -396,6 +412,7 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
 	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
 	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
 	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
+	.test_young		= kvm_mmu_notifier_test_young,
 	.change_pte		= kvm_mmu_notifier_change_pte,
 	.release		= kvm_mmu_notifier_release,
 };