mm: khugepaged: introduce khugepaged_enter_vma() helper

The khugepaged_enter_vma_merge() actually does as the same thing as the
khugepaged_enter() section called by shmem_mmap(), so consolidate them
into one helper and rename it to khugepaged_enter_vma().

Link: https://lkml.kernel.org/r/20220510203222.24246-8-shy828301@gmail.comSigned-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastmil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <song@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/khugepaged.h

@@ -14,7 +14,7 @@ extern bool hugepage_vma_check(struct vm_area_struct *vma,
 			       unsigned long vm_flags);
 extern void __khugepaged_enter(struct mm_struct *mm);
 extern void __khugepaged_exit(struct mm_struct *mm);
-extern void khugepaged_enter_vma_merge(struct vm_area_struct *vma,
+extern void khugepaged_enter_vma(struct vm_area_struct *vma,
 				 unsigned long vm_flags);
 extern void khugepaged_min_free_kbytes_update(void);
 #ifdef CONFIG_SHMEM
@@ -72,7 +72,7 @@ static inline void khugepaged_enter(struct vm_area_struct *vma,
 				    unsigned long vm_flags)
 {
 }
-static inline void khugepaged_enter_vma_merge(struct vm_area_struct *vma,
+static inline void khugepaged_enter_vma(struct vm_area_struct *vma,
 					unsigned long vm_flags)
 {
 }

mm/khugepaged.c

@@ -365,7 +365,7 @@ int hugepage_madvise(struct vm_area_struct *vma,
 		 * register it here without waiting a page fault that
 		 * may not happen any time soon.
 		 */
-		khugepaged_enter_vma_merge(vma, *vm_flags);
+		khugepaged_enter_vma(vma, *vm_flags);
 		break;
 	case MADV_NOHUGEPAGE:
 		*vm_flags &= ~VM_HUGEPAGE;
@@ -505,7 +505,7 @@ void __khugepaged_enter(struct mm_struct *mm)
 		wake_up_interruptible(&khugepaged_wait);
 }
 
-void khugepaged_enter_vma_merge(struct vm_area_struct *vma,
+void khugepaged_enter_vma(struct vm_area_struct *vma,
 			  unsigned long vm_flags)
 {
 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&

mm/mmap.c

@@ -1223,7 +1223,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
 					 end, prev->vm_pgoff, NULL, prev);
 		if (err)
 			return NULL;
-		khugepaged_enter_vma_merge(prev, vm_flags);
+		khugepaged_enter_vma(prev, vm_flags);
 		return prev;
 	}
 
@@ -1250,7 +1250,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
 		}
 		if (err)
 			return NULL;
-		khugepaged_enter_vma_merge(area, vm_flags);
+		khugepaged_enter_vma(area, vm_flags);
 		return area;
 	}
 
@@ -2450,7 +2450,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma_merge(vma, vma->vm_flags);
+	khugepaged_enter_vma(vma, vma->vm_flags);
 	validate_mm(mm);
 	return error;
 }
@@ -2528,7 +2528,7 @@ int expand_downwards(struct vm_area_struct *vma,
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma_merge(vma, vma->vm_flags);
+	khugepaged_enter_vma(vma, vma->vm_flags);
 	validate_mm(mm);
 	return error;
 }

mm/shmem.c

@@ -2232,11 +2232,7 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
 
 	file_accessed(file);
 	vma->vm_ops = &shmem_vm_ops;
-	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
-			((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
-			(vma->vm_end & HPAGE_PMD_MASK)) {
-		khugepaged_enter(vma, vma->vm_flags);
-	}
+	khugepaged_enter_vma(vma, vma->vm_flags);
 	return 0;
 }
 
@@ -4137,11 +4133,7 @@ int shmem_zero_setup(struct vm_area_struct *vma)
 	vma->vm_file = file;
 	vma->vm_ops = &shmem_vm_ops;
 
-	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
-			((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
-			(vma->vm_end & HPAGE_PMD_MASK)) {
-		khugepaged_enter(vma, vma->vm_flags);
-	}
+	khugepaged_enter_vma(vma, vma->vm_flags);
 
 	return 0;
 }