Thread (9 messages) read the whole thread 9 messages, 2 authors, 2021-02-09
STALE2000d

Revision v4 of 5 in this series.

Revisions (5)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current
  5. v5 [diff vs current]

[PATCH v4 4/5] mm: Use is_cow_mapping() across tree where proper

From: Peter Xu <peterx@redhat.com>
Date: 2021-02-09 03:13:04
Also in: lkml
Subsystem: drm driver for vmware virtual gpu, drm drivers, drm drivers and misc gpu patches, filesystems (vfs and infrastructure), hugetlb subsystem, memory management, memory mapping, proc filesystem, the rest · Maintainers: Zack Rusin, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Alexander Viro, Christian Brauner, Muchun Song, Oscar Salvador, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds

After is_cow_mapping() is exported in mm.h, replace some manual checks
elsewhere throughout the tree but start to use the new helper.

Cc: VMware Graphics <redacted>
Cc: Roland Scheidegger <redacted>
Cc: David Airlie <redacted>
Cc: Daniel Vetter <redacted>
Cc: Mike Kravetz <redacted>
Cc: Alexey Dobriyan <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 4 +---
 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c   | 2 +-
 fs/proc/task_mmu.c                         | 2 --
 mm/hugetlb.c                               | 4 +---
 4 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
index 0a900afc66ff..45c9c6a7f1d6 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
@@ -500,8 +500,6 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
 	vm_fault_t ret;
 	pgoff_t fault_page_size;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
-	bool is_cow_mapping =
-		(vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
 
 	switch (pe_size) {
 	case PE_SIZE_PMD:
@@ -518,7 +516,7 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
 	}
 
 	/* Always do write dirty-tracking and COW on PTE level. */
-	if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping))
+	if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping(vma->vm_flags)))
 		return VM_FAULT_FALLBACK;
 
 	ret = ttm_bo_vm_reserve(bo, vmf);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
index 3c03b1746661..cb9975889e2f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
@@ -49,7 +49,7 @@ int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_ops = &vmw_vm_ops;
 
 	/* Use VM_PFNMAP rather than VM_MIXEDMAP if not a COW mapping */
-	if ((vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) != VM_MAYWRITE)
+	if (!is_cow_mapping(vma->vm_flags))
 		vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP;
 
 	return 0;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 602e3a52884d..96c1682025f9 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1036,8 +1036,6 @@ struct clear_refs_private {
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 
-#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
-
 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 {
 	struct page *page;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 71ccec5c3817..620700f05ff4 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3733,15 +3733,13 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	pte_t *src_pte, *dst_pte, entry, dst_entry;
 	struct page *ptepage;
 	unsigned long addr;
-	int cow;
+	int cow = is_cow_mapping(vma->vm_flags);
 	struct hstate *h = hstate_vma(vma);
 	unsigned long sz = huge_page_size(h);
 	struct address_space *mapping = vma->vm_file->f_mapping;
 	struct mmu_notifier_range range;
 	int ret = 0;
 
-	cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
-
 	if (cow) {
 		mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src,
 					vma->vm_start,
-- 
2.26.2

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help