linux-kernel - [v4 PATCH 6/8] mm: khugepaged: make hugepage_vma

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Date:   Tue, 10 May 2022 13:32:20 -0700
From:   Yang Shi <shy828301@...il.com>
To:     vbabka@...e.cz, kirill.shutemov@...ux.intel.com,
        linmiaohe@...wei.com, songliubraving@...com, riel@...riel.com,
        willy@...radead.org, ziy@...dia.com, tytso@....edu,
        akpm@...ux-foundation.org
Cc:     shy828301@...il.com, linux-mm@...ck.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [v4 PATCH 6/8] mm: khugepaged: make hugepage_vma_check() non-static

The hugepage_vma_check() could be reused by khugepaged_enter() and
khugepaged_enter_vma_merge(), but it is static in khugepaged.c.
Make it non-static and declare it in khugepaged.h.

Suggested-by: Vlastimil Babka <vbabka@...e.cz>
Signed-off-by: Yang Shi <shy828301@...il.com>
---
 include/linux/khugepaged.h | 14 ++++++--------
 mm/khugepaged.c            | 25 +++++++++----------------
 2 files changed, 15 insertions(+), 24 deletions(-)

diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
index 0423d3619f26..c340f6bb39d6 100644
--- a/include/linux/khugepaged.h
+++ b/include/linux/khugepaged.h
@@ -3,8 +3,6 @@
 #define _LINUX_KHUGEPAGED_H
 
 #include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */
-#include <linux/shmem_fs.h>
-
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern struct attribute_group khugepaged_attr_group;
@@ -12,6 +10,8 @@ extern struct attribute_group khugepaged_attr_group;
 extern int khugepaged_init(void);
 extern void khugepaged_destroy(void);
 extern int start_stop_khugepaged(void);
+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,
@@ -55,13 +55,11 @@ static inline void khugepaged_exit(struct mm_struct *mm)
 static inline void khugepaged_enter(struct vm_area_struct *vma,
 				   unsigned long vm_flags)
 {
-	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
-		if ((khugepaged_always() ||
-		     (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) ||
-		     (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
-		    !(vm_flags & VM_NOHUGEPAGE) &&
-		    !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
+	    khugepaged_enabled()) {
+		if (hugepage_vma_check(vma, vm_flags))
 			__khugepaged_enter(vma->vm_mm);
+	}
 }
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 7815218ab960..dec449339964 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -437,8 +437,8 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
 	return atomic_read(&mm->mm_users) == 0;
 }
 
-static bool hugepage_vma_check(struct vm_area_struct *vma,
-			       unsigned long vm_flags)
+bool hugepage_vma_check(struct vm_area_struct *vma,
+			unsigned long vm_flags)
 {
 	if (!transhuge_vma_enabled(vma, vm_flags))
 		return false;
@@ -508,20 +508,13 @@ void __khugepaged_enter(struct mm_struct *mm)
 void khugepaged_enter_vma_merge(struct vm_area_struct *vma,
 			       unsigned long vm_flags)
 {
-	unsigned long hstart, hend;
-
-	/*
-	 * khugepaged only supports read-only files for non-shmem files.
-	 * khugepaged does not yet work on special mappings. And
-	 * file-private shmem THP is not supported.
-	 */
-	if (!hugepage_vma_check(vma, vm_flags))
-		return;
-
-	hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
-	hend = vma->vm_end & HPAGE_PMD_MASK;
-	if (hstart < hend)
-		khugepaged_enter(vma, vm_flags);
+	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
+	    khugepaged_enabled() &&
+	    (((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
+	     (vma->vm_end & HPAGE_PMD_MASK))) {
+		if (hugepage_vma_check(vma, vm_flags))
+			__khugepaged_enter(vma->vm_mm);
+	}
 }
 
 void __khugepaged_exit(struct mm_struct *mm)
-- 
2.26.3