---

yaml --- r: 230812 b: refs/heads/master c: 60ab324 h: refs/heads/master v: v3
git-mirror · Jan 14, 2011 · a20e586 · a20e586
1 parent aa1a7fa
commit a20e586
Show file tree

Hide file tree

Showing 4 changed files with 25 additions and 8 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a664b2d8555c659127bf8fe049a58449d394a707
+refs/heads/master: 60ab3244ec85c44276c585a2a20d3750402e1cf4
diff --git a/trunk/include/linux/huge_mm.h b/trunk/include/linux/huge_mm.h
@@ -105,7 +105,8 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
 #if HPAGE_PMD_ORDER > MAX_ORDER
 #error "hugepages can't be allocated by the buddy allocator"
 #endif
-extern int hugepage_madvise(unsigned long *vm_flags, int advice);
+extern int hugepage_madvise(struct vm_area_struct *vma,
+			    unsigned long *vm_flags, int advice);
 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
 				    unsigned long start,
 				    unsigned long end,
@@ -143,7 +144,8 @@ static inline int split_huge_page(struct page *page)
 	do { } while (0)
 #define wait_split_huge_page(__anon_vma, __pmd)	\
 	do { } while (0)
-static inline int hugepage_madvise(unsigned long *vm_flags, int advice)
+static inline int hugepage_madvise(struct vm_area_struct *vma,
+				   unsigned long *vm_flags, int advice)
 {
 	BUG();
 	return 0;

diff --git a/trunk/mm/huge_memory.c b/trunk/mm/huge_memory.c
@@ -1389,7 +1389,8 @@ int split_huge_page(struct page *page)
 	return ret;
 }
 
-int hugepage_madvise(unsigned long *vm_flags, int advice)
+int hugepage_madvise(struct vm_area_struct *vma,
+		     unsigned long *vm_flags, int advice)
 {
 	switch (advice) {
 	case MADV_HUGEPAGE:
@@ -1404,6 +1405,13 @@ int hugepage_madvise(unsigned long *vm_flags, int advice)
 			return -EINVAL;
 		*vm_flags &= ~VM_NOHUGEPAGE;
 		*vm_flags |= VM_HUGEPAGE;
+		/*
+		 * If the vma become good for khugepaged to scan,
+		 * register it here without waiting a page fault that
+		 * may not happen any time soon.
+		 */
+		if (unlikely(khugepaged_enter_vma_merge(vma)))
+			return -ENOMEM;
 		break;
 	case MADV_NOHUGEPAGE:
 		/*
@@ -1417,6 +1425,11 @@ int hugepage_madvise(unsigned long *vm_flags, int advice)
 			return -EINVAL;
 		*vm_flags &= ~VM_HUGEPAGE;
 		*vm_flags |= VM_NOHUGEPAGE;
+		/*
+		 * Setting VM_NOHUGEPAGE will prevent khugepaged from scanning
+		 * this vma even if we leave the mm registered in khugepaged if
+		 * it got registered before VM_NOHUGEPAGE was set.
+		 */
 		break;
 	}
 
@@ -1784,7 +1797,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	if (address < hstart || address + HPAGE_PMD_SIZE > hend)
 		goto out;
 
-	if (!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+	if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+	    (vma->vm_flags & VM_NOHUGEPAGE))
 		goto out;
 
 	/* VM_PFNMAP vmas may have vm_ops null but vm_file set */
@@ -2007,8 +2021,9 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 			break;
 		}
 
-		if (!(vma->vm_flags & VM_HUGEPAGE) &&
-		    !khugepaged_always()) {
+		if ((!(vma->vm_flags & VM_HUGEPAGE) &&
+		     !khugepaged_always()) ||
+		    (vma->vm_flags & VM_NOHUGEPAGE)) {
 			progress++;
 			continue;
 		}

diff --git a/trunk/mm/madvise.c b/trunk/mm/madvise.c
@@ -73,7 +73,7 @@ static long madvise_behavior(struct vm_area_struct * vma,
 		break;
 	case MADV_HUGEPAGE:
 	case MADV_NOHUGEPAGE:
-		error = hugepage_madvise(&new_flags, behavior);
+		error = hugepage_madvise(vma, &new_flags, behavior);
 		if (error)
 			goto out;
 		break;