mm: khugepaged: reorg some khugepaged helpers

The khugepaged_{enabled|always|req_madv} are not khugepaged only anymore,
move them to huge_mm.h and rename to hugepage_flags_xxx, and remove
khugepaged_req_madv due to no users.

Also move khugepaged_defrag to khugepaged.c since its only caller is in
that file, it doesn't have to be in a header file.

Link: https://lkml.kernel.org/r/20220616174840.1202070-7-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zach O'Keefe <zokeefe@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/huge_mm.h

@@ -116,6 +116,14 @@ extern struct kobj_attribute shmem_enabled_attr;
 
 extern unsigned long transparent_hugepage_flags;
 
+#define hugepage_flags_enabled()					       \
+	(transparent_hugepage_flags &				       \
+	 ((1<<TRANSPARENT_HUGEPAGE_FLAG) |		       \
+	  (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
+#define hugepage_flags_always()				\
+	(transparent_hugepage_flags &			\
+	 (1<<TRANSPARENT_HUGEPAGE_FLAG))
+
 /*
  * Do the below checks:
  *   - For file vma, check if the linear page offset of vma is

include/linux/khugepaged.h

@@ -24,20 +24,6 @@ static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
 }
 #endif
 
-#define khugepaged_enabled()					       \
-	(transparent_hugepage_flags &				       \
-	 ((1<<TRANSPARENT_HUGEPAGE_FLAG) |		       \
-	  (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)))
-#define khugepaged_always()				\
-	(transparent_hugepage_flags &			\
-	 (1<<TRANSPARENT_HUGEPAGE_FLAG))
-#define khugepaged_req_madv()					\
-	(transparent_hugepage_flags &				\
-	 (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
-#define khugepaged_defrag()					\
-	(transparent_hugepage_flags &				\
-	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
-
 static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
 {
 	if (test_bit(MMF_VM_HUGEPAGE, &oldmm->flags))

mm/huge_memory.c

@@ -120,11 +120,11 @@ bool hugepage_vma_check(struct vm_area_struct *vma,
 	if (!in_pf && shmem_file(vma->vm_file))
 		return shmem_huge_enabled(vma);
 
-	if (!khugepaged_enabled())
+	if (!hugepage_flags_enabled())
 		return false;
 
 	/* THP settings require madvise. */
-	if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+	if (!(vm_flags & VM_HUGEPAGE) && !hugepage_flags_always())
 		return false;
 
 	/* Only regular file is valid */

mm/khugepaged.c

@@ -465,7 +465,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma,
 			  unsigned long vm_flags)
 {
 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-	    khugepaged_enabled()) {
+	    hugepage_flags_enabled()) {
 		if (hugepage_vma_check(vma, vm_flags, false, false))
 			__khugepaged_enter(vma->vm_mm);
 	}
@@ -761,6 +761,10 @@ static bool khugepaged_scan_abort(int nid)
 	return false;
 }
 
+#define khugepaged_defrag()					\
+	(transparent_hugepage_flags &				\
+	 (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG))
+
 /* Defrag for khugepaged will enter direct reclaim/compaction if necessary */
 static inline gfp_t alloc_hugepage_khugepaged_gfpmask(void)
 {
@@ -858,7 +862,7 @@ static struct page *khugepaged_alloc_hugepage(bool *wait)
 			khugepaged_alloc_sleep();
 		} else
 			count_vm_event(THP_COLLAPSE_ALLOC);
-	} while (unlikely(!hpage) && likely(khugepaged_enabled()));
+	} while (unlikely(!hpage) && likely(hugepage_flags_enabled()));
 
 	return hpage;
 }
@@ -2172,7 +2176,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 static int khugepaged_has_work(void)
 {
 	return !list_empty(&khugepaged_scan.mm_head) &&
-		khugepaged_enabled();
+		hugepage_flags_enabled();
 }
 
 static int khugepaged_wait_event(void)
@@ -2237,7 +2241,7 @@ static void khugepaged_wait_work(void)
 		return;
 	}
 
-	if (khugepaged_enabled())
+	if (hugepage_flags_enabled())
 		wait_event_freezable(khugepaged_wait, khugepaged_wait_event());
 }
 
@@ -2268,7 +2272,7 @@ static void set_recommended_min_free_kbytes(void)
 	int nr_zones = 0;
 	unsigned long recommended_min;
 
-	if (!khugepaged_enabled()) {
+	if (!hugepage_flags_enabled()) {
 		calculate_min_free_kbytes();
 		goto update_wmarks;
 	}
@@ -2318,7 +2322,7 @@ int start_stop_khugepaged(void)
 	int err = 0;
 
 	mutex_lock(&khugepaged_mutex);
-	if (khugepaged_enabled()) {
+	if (hugepage_flags_enabled()) {
 		if (!khugepaged_thread)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
 							"khugepaged");
@@ -2344,7 +2348,7 @@ int start_stop_khugepaged(void)
 void khugepaged_min_free_kbytes_update(void)
 {
 	mutex_lock(&khugepaged_mutex);
-	if (khugepaged_enabled() && khugepaged_thread)
+	if (hugepage_flags_enabled() && khugepaged_thread)
 		set_recommended_min_free_kbytes();
 	mutex_unlock(&khugepaged_mutex);
 }