9 files changed, 30 insertions, 24 deletions

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 0d4d8bec0df4..b44b36e0c293 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -285,8 +285,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
          * It's fine to use that for setting breakpoints in the vDSO code
          * pages though
          */
-        vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE |
-                VM_MAYEXEC | VM_RESERVED;
+        vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
         vma->vm_flags |= mm->def_flags;
         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
         vma->vm_ops = &vdso_vmops;
diff --git a/arch/sparc/mm/generic.c b/arch/sparc/mm/generic.c
index 9604893ffdbd..0410bae681f8 100644
--- a/arch/sparc/mm/generic.c
+++ b/arch/sparc/mm/generic.c
@@ -74,7 +74,7 @@ int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
 
         /* See comment in mm/memory.c remap_pfn_range */
-        vma->vm_flags |= VM_IO | VM_RESERVED;
+        vma->vm_flags |= VM_IO | VM_RESERVED | VM_UNPAGED;
 
         prot = __pgprot(pg_iobits);
         offset -= from;
diff --git a/arch/sparc64/mm/generic.c b/arch/sparc64/mm/generic.c
index 112c316e7cd2..8fd4cb1f050a 100644
--- a/arch/sparc64/mm/generic.c
+++ b/arch/sparc64/mm/generic.c
@@ -128,7 +128,7 @@ int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
 
         /* See comment in mm/memory.c remap_pfn_range */
-        vma->vm_flags |= VM_IO | VM_RESERVED;
+        vma->vm_flags |= VM_IO | VM_RESERVED | VM_UNPAGED;
 
         prot = __pgprot(pg_iobits);
         offset -= from;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9701210c6680..f0cdfd18db55 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -144,7 +144,8 @@ extern unsigned int kobjsize(const void *objp);
 
 #define VM_GROWSDOWN    0x00000100      /* general info on the segment */
 #define VM_GROWSUP      0x00000200
-#define VM_SHM          0x00000400      /* shared memory area, don't swap out */
+#define VM_SHM          0x00000000      /* Means nothing: delete it later */
+#define VM_UNPAGED      0x00000400      /* Pages managed without map count */
 #define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
 
 #define VM_EXECUTABLE   0x00001000
@@ -157,7 +158,7 @@ extern unsigned int kobjsize(const void *objp);
 
 #define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
 #define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
-#define VM_RESERVED     0x00080000      /* Pages managed in a special way */
+#define VM_RESERVED     0x00080000      /* Count as reserved_vm like IO */
 #define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
 #define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
 #define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
diff --git a/mm/fremap.c b/mm/fremap.c
index d862be3bc3e3..94254c5d7a18 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -65,7 +65,7 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
         pte_t pte_val;
         spinlock_t *ptl;
 
-        BUG_ON(vma->vm_flags & VM_RESERVED);
+        BUG_ON(vma->vm_flags & VM_UNPAGED);
 
         pgd = pgd_offset(mm, addr);
         pud = pud_alloc(mm, pgd, addr);
@@ -122,7 +122,7 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
         pte_t pte_val;
         spinlock_t *ptl;
 
-        BUG_ON(vma->vm_flags & VM_RESERVED);
+        BUG_ON(vma->vm_flags & VM_UNPAGED);
 
         pgd = pgd_offset(mm, addr);
         pud = pud_alloc(mm, pgd, addr);
diff --git a/mm/madvise.c b/mm/madvise.c
index 17aaf3e16449..328a3bcce527 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -126,7 +126,7 @@ static long madvise_dontneed(struct vm_area_struct * vma,
                              unsigned long start, unsigned long end)
 {
         *prev = vma;
-        if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_RESERVED))
+        if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_UNPAGED))
                 return -EINVAL;
 
         if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
diff --git a/mm/memory.c b/mm/memory.c
index cfce5f1f30f2..ece04963158e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -334,7 +334,7 @@ static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss)
 
 /*
  * This function is called to print an error when a pte in a
- * !VM_RESERVED region is found pointing to an invalid pfn (which
+ * !VM_UNPAGED region is found pointing to an invalid pfn (which
  * is an error.
  *
  * The calling function must still handle the error.
@@ -381,15 +381,15 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
                 goto out_set_pte;
         }
 
-        /* If the region is VM_RESERVED, the mapping is not
+        /* If the region is VM_UNPAGED, the mapping is not
          * mapped via rmap - duplicate the pte as is.
          */
-        if (vm_flags & VM_RESERVED)
+        if (vm_flags & VM_UNPAGED)
                 goto out_set_pte;
 
         pfn = pte_pfn(pte);
         /* If the pte points outside of valid memory but
-         * the region is not VM_RESERVED, we have a problem.
+         * the region is not VM_UNPAGED, we have a problem.
          */
         if (unlikely(!pfn_valid(pfn))) {
                 print_bad_pte(vma, pte, addr);
@@ -528,7 +528,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
          * readonly mappings. The tradeoff is that copy_page_range is more
          * efficient than faulting.
          */
-        if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_RESERVED))) {
+        if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_UNPAGED))) {
                 if (!vma->anon_vma)
                         return 0;
         }
@@ -572,7 +572,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 
                         (*zap_work) -= PAGE_SIZE;
 
-                        if (!(vma->vm_flags & VM_RESERVED)) {
+                        if (!(vma->vm_flags & VM_UNPAGED)) {
                                 unsigned long pfn = pte_pfn(ptent);
                                 if (unlikely(!pfn_valid(pfn)))
                                         print_bad_pte(vma, ptent, addr);
@@ -1191,10 +1191,16 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
          * rest of the world about it:
          *   VM_IO tells people not to look at these pages
          *      (accesses can have side effects).
-         *   VM_RESERVED tells the core MM not to "manage" these pages
-         *      (e.g. refcount, mapcount, try to swap them out).
+         *   VM_RESERVED is specified all over the place, because
+         *      in 2.4 it kept swapout's vma scan off this vma; but
+         *      in 2.6 the LRU scan won't even find its pages, so this
+         *      flag means no more than count its pages in reserved_vm,
+         *      and omit it from core dump, even when VM_IO turned off.
+         *   VM_UNPAGED tells the core MM not to "manage" these pages
+         *      (e.g. refcount, mapcount, try to swap them out): in
+         *      particular, zap_pte_range does not try to free them.
          */
-        vma->vm_flags |= VM_IO | VM_RESERVED;
+        vma->vm_flags |= VM_IO | VM_RESERVED | VM_UNPAGED;
 
         BUG_ON(addr >= end);
         pfn -= addr >> PAGE_SHIFT;
@@ -1276,7 +1282,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
         pte_t entry;
         int ret = VM_FAULT_MINOR;
 
-        BUG_ON(vma->vm_flags & VM_RESERVED);
+        BUG_ON(vma->vm_flags & VM_UNPAGED);
 
         if (unlikely(!pfn_valid(pfn))) {
                 /*
@@ -1924,7 +1930,7 @@ retry:
                         inc_mm_counter(mm, anon_rss);
                         lru_cache_add_active(new_page);
                         page_add_anon_rmap(new_page, vma, address);
-                } else if (!(vma->vm_flags & VM_RESERVED)) {
+                } else if (!(vma->vm_flags & VM_UNPAGED)) {
                         inc_mm_counter(mm, file_rss);
                         page_add_file_rmap(new_page);
                 }
@@ -2203,7 +2209,7 @@ static int __init gate_vma_init(void)
         gate_vma.vm_start = FIXADDR_USER_START;
         gate_vma.vm_end = FIXADDR_USER_END;
         gate_vma.vm_page_prot = PAGE_READONLY;
-        gate_vma.vm_flags = VM_RESERVED;
+        gate_vma.vm_flags = 0;
         return 0;
 }
 __initcall(gate_vma_init);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5abc57c2b8bd..5609a31bdf22 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -269,7 +269,7 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
         first = find_vma(mm, start);
         if (!first)
                 return ERR_PTR(-EFAULT);
-        if (first->vm_flags & VM_RESERVED)
+        if (first->vm_flags & VM_UNPAGED)
                 return ERR_PTR(-EACCES);
         prev = NULL;
         for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
diff --git a/mm/msync.c b/mm/msync.c
index 0e040e9c39d8..b3f4caf3010b 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -97,9 +97,9 @@ static void msync_page_range(struct vm_area_struct *vma,
         /* For hugepages we can't go walking the page table normally,
          * but that's ok, hugetlbfs is memory based, so we don't need
          * to do anything more on an msync().
-         * Can't do anything with VM_RESERVED regions either.
+         * Can't do anything with VM_UNPAGED regions either.
          */
-        if (vma->vm_flags & (VM_HUGETLB|VM_RESERVED))
+        if (vma->vm_flags & (VM_HUGETLB|VM_UNPAGED))
                 return;
 
         BUG_ON(addr >= end);