mm: kill vma flag VM_RESERVED and mm->reserved_vm counter

A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:

 | effect                 | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump      | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock           | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP

This patch removes reserved_vm counter from mm_struct.  Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.

Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.

remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.

[akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 4 insertions, 4 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 2b72d26e2e4b..e800dec958c3 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1135,7 +1135,7 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
         }
 
         /* Do not dump I/O mapped devices or special mappings */
-        if (vma->vm_flags & (VM_IO | VM_RESERVED))
+        if (vma->vm_flags & VM_IO)
                 return 0;
 
         /* By default, dump shared memory if mapped from an anonymous file. */
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 08d812b32282..262db114ff01 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1205,7 +1205,7 @@ static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
         int dump_ok;
 
         /* Do not dump I/O mapped devices or special mappings */
-        if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
+        if (vma->vm_flags & VM_IO) {
                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
                 return 0;
         }
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 9460120a5170..0a0ab8e21b19 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -110,7 +110,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
          * way when do_mmap_pgoff unwinds (may be important on powerpc
          * and ia64).
          */
-        vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
+        vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND | VM_DONTDUMP;
         vma->vm_ops = &hugetlb_vm_ops;
 
         if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 4540b8f76f16..79827ce03e3b 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -54,7 +54,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
                 "VmPTE:\t%8lu kB\n"
                 "VmSwap:\t%8lu kB\n",
                 hiwater_vm << (PAGE_SHIFT-10),
-                (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
+                total_vm << (PAGE_SHIFT-10),
                 mm->locked_vm << (PAGE_SHIFT-10),
                 mm->pinned_vm << (PAGE_SHIFT-10),
                 hiwater_rss << (PAGE_SHIFT-10),