[PATCH] remove VM_DONTCOPY bogosities
Now that it's madvisable, remove two pieces of VM_DONTCOPY bogosity:
1. There was and is no logical reason why VM_DONTCOPY should be in the
list of flags which forbid vma merging (and those drivers which set
it are also setting VM_IO, which itself forbids the merge).
2. It's hard to understand the purpose of the VM_HUGETLB, VM_DONTCOPY
block in vm_stat_account: but never mind, it's under CONFIG_HUGETLB,
which (unlike CONFIG_HUGETLB_PAGE or CONFIG_HUGETLBFS) has never been
defined.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index 47556d2..0eb9894 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -612,7 +612,7 @@
* If the vma has a ->close operation then the driver probably needs to release
* per-vma resources, so we don't attempt to merge those.
*/
-#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
+#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
static inline int is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags)
@@ -845,14 +845,6 @@
const unsigned long stack_flags
= VM_STACK_FLAGS & (VM_GROWSUP|VM_GROWSDOWN);
-#ifdef CONFIG_HUGETLB
- if (flags & VM_HUGETLB) {
- if (!(flags & VM_DONTCOPY))
- mm->shared_vm += pages;
- return;
- }
-#endif /* CONFIG_HUGETLB */
-
if (file) {
mm->shared_vm += pages;
if ((flags & (VM_EXEC|VM_WRITE)) == VM_EXEC)