On Mon, Oct 09, 2023 at 05:45:26PM +0200, Vlastimil Babka wrote:
> On 10/8/23 22:23, Lorenzo Stoakes wrote:
> > Now the vma_merge()/split_vma() pattern has been abstracted, we use it
>
> "it" refers to split_vma() only so "the latter" or "split_vma()"?
>
I mean to say the pattern of attempting vma_merge(), then if that fails,
splitting as necessary. I will try to clarify the language in v2.
> > entirely internally within mm/mmap.c, so make the function static. We also
> > no longer need vma_merge() anywhere else except mm/mremap.c, so make it
> > internal.
> >
> > In addition, the split_vma() nommu variant also need not be exported.
> >
> > Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
>
Thanks!
@@ -3237,16 +3237,7 @@ extern int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct vm_area_struct *next);
extern int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, pgoff_t pgoff);
-extern struct vm_area_struct *vma_merge(struct vma_iterator *vmi,
- struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,
- unsigned long end, unsigned long vm_flags, struct anon_vma *,
- struct file *, pgoff_t, struct mempolicy *, struct vm_userfaultfd_ctx,
- struct anon_vma_name *);
extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
-extern int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
- unsigned long addr, int new_below);
-extern int split_vma(struct vma_iterator *vmi, struct vm_area_struct *,
- unsigned long addr, int new_below);
extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void unlink_file_vma(struct vm_area_struct *);
extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
@@ -1011,6 +1011,15 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmd,
unsigned int flags);
+/*
+ * mm/mmap.c
+ */
+struct vm_area_struct *vma_merge(struct vma_iterator *vmi,
+ struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,
+ unsigned long end, unsigned long vm_flags, struct anon_vma *,
+ struct file *, pgoff_t, struct mempolicy *, struct vm_userfaultfd_ctx,
+ struct anon_vma_name *);
+
enum {
/* mark page accessed */
FOLL_TOUCH = 1 << 16,
@@ -2346,8 +2346,8 @@ static void unmap_region(struct mm_struct *mm, struct ma_state *mas,
* has already been checked or doesn't make sense to fail.
* VMA Iterator will point to the end VMA.
*/
-int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long addr, int new_below)
+static int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
{
struct vma_prepare vp;
struct vm_area_struct *new;
@@ -2428,8 +2428,8 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
* Split a vma into two pieces at address 'addr', a new vma is allocated
* either for the first part or the tail.
*/
-int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long addr, int new_below)
+static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
{
if (vma->vm_mm->map_count >= sysctl_max_map_count)
return -ENOMEM;
@@ -1305,8 +1305,8 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
* split a vma into two pieces at address 'addr', a new vma is allocated either
* for the first part or the tail.
*/
-int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long addr, int new_below)
+static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
{
struct vm_area_struct *new;
struct vm_region *region;