[RFC PATCH 2/4] mm: pass VMA parameter to hugepage_global_{enabled,always}()

[Yafang Shao <laoar.shao@gmail.com>]

We will use the new @vma parameter to determine whether THP can be used.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 mm/huge_memory.c |  8 ++++----
 mm/internal.h    |  8 ++++++--
 mm/khugepaged.c  | 18 +++++++++---------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 39afa14af2f2..7a4a968c7874 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -176,8 +176,8 @@ static unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 		 * were already handled in thp_vma_allowable_orders().
 		 */
 		if (enforce_sysfs &&
-		    (!hugepage_global_enabled() || (!(vm_flags & VM_HUGEPAGE) &&
-						    !hugepage_global_always())))
+		    (!hugepage_global_enabled(vma) || (!(vm_flags & VM_HUGEPAGE) &&
+						      !hugepage_global_always(vma))))
 			return 0;
 
 		/*
@@ -234,8 +234,8 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
 
 		if (vm_flags & VM_HUGEPAGE)
 			mask |= READ_ONCE(huge_anon_orders_madvise);
-		if (hugepage_global_always() ||
-		    ((vm_flags & VM_HUGEPAGE) && hugepage_global_enabled()))
+		if (hugepage_global_always(vma) ||
+		    ((vm_flags & VM_HUGEPAGE) && hugepage_global_enabled(vma)))
 			mask |= READ_ONCE(huge_anon_orders_inherit);
 
 		orders &= mask;
diff --git a/mm/internal.h b/mm/internal.h
index 462d85c2ba7b..aa698a11dd68 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1626,14 +1626,18 @@ static inline bool reclaim_pt_is_enabled(unsigned long start, unsigned long end,
 #endif /* CONFIG_PT_RECLAIM */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static inline bool hugepage_global_enabled(void)
+/*
+ * Checks whether a given @vma can use THP. If @vma is NULL, the check is
+ * performed globally by khugepaged during a system-wide scan.
+ */
+static inline bool hugepage_global_enabled(struct vm_area_struct *vma)
 {
 	return transparent_hugepage_flags &
 			((1<<TRANSPARENT_HUGEPAGE_FLAG) |
 			(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG));
 }
 
-static inline bool hugepage_global_always(void)
+static inline bool hugepage_global_always(struct vm_area_struct *vma)
 {
 	return transparent_hugepage_flags &
 			(1<<TRANSPARENT_HUGEPAGE_FLAG);
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index cc945c6ab3bd..b85e36ddd7db 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -413,7 +413,7 @@ static inline int hpage_collapse_test_exit_or_disable(struct mm_struct *mm)
 	       test_bit(MMF_DISABLE_THP, &mm->flags);
 }
 
-static bool hugepage_pmd_enabled(void)
+static bool hugepage_pmd_enabled(struct vm_area_struct *vma)
 {
 	/*
 	 * We cover the anon, shmem and the file-backed case here; file-backed
@@ -423,14 +423,14 @@ static bool hugepage_pmd_enabled(void)
 	 * except when the global shmem_huge is set to SHMEM_HUGE_DENY.
 	 */
 	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
-	    hugepage_global_enabled())
+	    hugepage_global_enabled(vma))
 		return true;
 	if (test_bit(PMD_ORDER, &huge_anon_orders_always))
 		return true;
 	if (test_bit(PMD_ORDER, &huge_anon_orders_madvise))
 		return true;
 	if (test_bit(PMD_ORDER, &huge_anon_orders_inherit) &&
-	    hugepage_global_enabled())
+	    hugepage_global_enabled(vma))
 		return true;
 	if (IS_ENABLED(CONFIG_SHMEM) && shmem_hpage_pmd_enabled())
 		return true;
@@ -473,7 +473,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma,
 			  unsigned long vm_flags)
 {
 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-	    hugepage_pmd_enabled()) {
+	    hugepage_pmd_enabled(vma)) {
 		if (thp_vma_allowable_order(vma, vm_flags, TVA_ENFORCE_SYSFS,
 					    PMD_ORDER))
 			__khugepaged_enter(vma->vm_mm);
@@ -2516,7 +2516,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 
 static int khugepaged_has_work(void)
 {
-	return !list_empty(&khugepaged_scan.mm_head) && hugepage_pmd_enabled();
+	return !list_empty(&khugepaged_scan.mm_head) && hugepage_pmd_enabled(NULL);
 }
 
 static int khugepaged_wait_event(void)
@@ -2589,7 +2589,7 @@ static void khugepaged_wait_work(void)
 		return;
 	}
 
-	if (hugepage_pmd_enabled())
+	if (hugepage_pmd_enabled(NULL))
 		wait_event_freezable(khugepaged_wait, khugepaged_wait_event());
 }
 
@@ -2620,7 +2620,7 @@ static void set_recommended_min_free_kbytes(void)
 	int nr_zones = 0;
 	unsigned long recommended_min;
 
-	if (!hugepage_pmd_enabled()) {
+	if (!hugepage_pmd_enabled(NULL)) {
 		calculate_min_free_kbytes();
 		goto update_wmarks;
 	}
@@ -2670,7 +2670,7 @@ int start_stop_khugepaged(void)
 	int err = 0;
 
 	mutex_lock(&khugepaged_mutex);
-	if (hugepage_pmd_enabled()) {
+	if (hugepage_pmd_enabled(NULL)) {
 		if (!khugepaged_thread)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
 							"khugepaged");
@@ -2696,7 +2696,7 @@ int start_stop_khugepaged(void)
 void khugepaged_min_free_kbytes_update(void)
 {
 	mutex_lock(&khugepaged_mutex);
-	if (hugepage_pmd_enabled() && khugepaged_thread)
+	if (hugepage_pmd_enabled(NULL) && khugepaged_thread)
 		set_recommended_min_free_kbytes();
 	mutex_unlock(&khugepaged_mutex);
 }
-- 
2.43.5