mm: re-architect the VM_UNPAGED logic
This replaces the (in my opinion horrible) VM_UNMAPPED logic with very
explicit support for a "remapped page range" aka VM_PFNMAP. It allows a
VM area to contain an arbitrary range of page table entries that the VM
never touches, and never considers to be normal pages.
Any user of "remap_pfn_range()" automatically gets this new
functionality, and doesn't even have to mark the pages reserved or
indeed mark them any other way. It just works. As a side effect, doing
mmap() on /dev/mem works for arbitrary ranges.
Sparc update from David in the next commit.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5609a31..bec88c8 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -189,17 +189,15 @@
orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
- unsigned long pfn;
+ struct page *page;
unsigned int nid;
if (!pte_present(*pte))
continue;
- pfn = pte_pfn(*pte);
- if (!pfn_valid(pfn)) {
- print_bad_pte(vma, *pte, addr);
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
continue;
- }
- nid = pfn_to_nid(pfn);
+ nid = page_to_nid(page);
if (!node_isset(nid, *nodes))
break;
} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -269,8 +267,6 @@
first = find_vma(mm, start);
if (!first)
return ERR_PTR(-EFAULT);
- if (first->vm_flags & VM_UNPAGED)
- return ERR_PTR(-EACCES);
prev = NULL;
for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
if (!vma->vm_next && vma->vm_end < end)
