Re: [PATCH v2 0/3] Some cleanups for shmem

[Andrew Morton]

On Sat, 13 Jul 2024 21:24:19 +0800 Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote:

> Changes from v1:
>  - Add a dummy function in case CONFIG_TRANSPARENT_HUGEPAGE is not
>  enabled, which fixes a building error reported by kernel test robot.

The only difference I'm seeing from the v1 series is the below update
to [3/3]:

--- a/mm/shmem.c~mm-shmem-move-shmem_huge_global_enabled-into-shmem_allowable_huge_orders-v2
+++ a/mm/shmem.c
@@ -549,10 +549,9 @@ static bool shmem_confirm_swap(struct ad
 static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER;
 
 static bool __shmem_huge_global_enabled(struct inode *inode, pgoff_t index,
-					bool shmem_huge_force, struct vm_area_struct *vma,
+					bool shmem_huge_force, struct mm_struct *mm,
 					unsigned long vm_flags)
 {
-	struct mm_struct *mm = vma ? vma->vm_mm : NULL;
 	loff_t i_size;
 
 	if (!S_ISREG(inode->i_mode))
@@ -583,14 +582,14 @@ static bool __shmem_huge_global_enabled(
 }
 
 static bool shmem_huge_global_enabled(struct inode *inode, pgoff_t index,
-		   bool shmem_huge_force, struct vm_area_struct *vma,
+		   bool shmem_huge_force, struct mm_struct *mm,
 		   unsigned long vm_flags)
 {
 	if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER)
 		return false;
 
 	return __shmem_huge_global_enabled(inode, index, shmem_huge_force,
-					   vma, vm_flags);
+					   mm, vm_flags);
 }
 
 #if defined(CONFIG_SYSFS)
@@ -775,7 +774,7 @@ static unsigned long shmem_unused_huge_s
 }
 
 static bool shmem_huge_global_enabled(struct inode *inode, pgoff_t index,
-		bool shmem_huge_force, struct vm_area_struct *vma,
+		bool shmem_huge_force, struct mm_struct *mm,
 		unsigned long vm_flags)
 {
 	return false;
@@ -1638,6 +1637,7 @@ unsigned long shmem_allowable_huge_order
 	unsigned long mask = READ_ONCE(huge_shmem_orders_always);
 	unsigned long within_size_orders = READ_ONCE(huge_shmem_orders_within_size);
 	unsigned long vm_flags = vma ? vma->vm_flags : 0;
+	struct mm_struct *fault_mm = vma ? vma->vm_mm : NULL;
 	/*
 	 * Check all the (large) orders below HPAGE_PMD_ORDER + 1 that
 	 * are enabled for this vma.
@@ -1656,7 +1656,7 @@ unsigned long shmem_allowable_huge_order
 		return 0;
 
 	global_huge = shmem_huge_global_enabled(inode, index, shmem_huge_force,
-						vma, vm_flags);
+						fault_mm, vm_flags);
 	if (!vma || !vma_is_anon_shmem(vma)) {
 		/*
 		 * For tmpfs, we now only support PMD sized THP if huge page
_