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.

[[email protected]: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Carsten Otte <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Cyrill Gorcunov <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Morris <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Kentaro Takeda <[email protected]>
Cc: Matt Helsley <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Robert Richter <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Venkatesh Pallipadi <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/video/68328fb.c

@@ -400,7 +400,7 @@ static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 #ifndef MMU
 	/* this is uClinux (no MMU) specific code */
 
-	vma->vm_flags |= VM_RESERVED;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_start = videomemory;
 
 	return 0;

drivers/video/aty/atyfb_base.c

@@ -1942,8 +1942,7 @@ static int atyfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	off = vma->vm_pgoff << PAGE_SHIFT;
 	size = vma->vm_end - vma->vm_start;
 
-	/* To stop the swapper from even considering these pages. */
-	vma->vm_flags |= (VM_IO | VM_RESERVED);
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
 
 	if (((vma->vm_pgoff == 0) && (size == info->fix.smem_len)) ||
 	    ((off == info->fix.smem_len) && (size == PAGE_SIZE)))

drivers/video/fb-puv3.c

@@ -653,9 +653,8 @@ int unifb_mmap(struct fb_info *info,
 				vma->vm_page_prot))
 		return -EAGAIN;
 
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
 	return 0;
-
 }
 
 static struct fb_ops unifb_ops = {

drivers/video/fb_defio.c

@@ -166,7 +166,7 @@ static const struct address_space_operations fb_deferred_io_aops = {
 static int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
 	vma->vm_ops = &fb_deferred_io_vm_ops;
-	vma->vm_flags |= ( VM_RESERVED | VM_DONTEXPAND );
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	if (!(info->flags & FBINFO_VIRTFB))
 		vma->vm_flags |= VM_IO;
 	vma->vm_private_data = info;

drivers/video/fbmem.c

@@ -1410,8 +1410,7 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 		return -EINVAL;
 	off += start;
 	vma->vm_pgoff = off >> PAGE_SHIFT;
-	/* This is an IO map - tell maydump to skip this VMA */
-	vma->vm_flags |= VM_IO | VM_RESERVED;
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by io_remap_pfn_range()*/
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	fb_pgprotect(file, vma, off);
 	if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,

drivers/video/gbefb.c

@@ -1024,7 +1024,7 @@ static int gbefb_mmap(struct fb_info *info,
 	pgprot_val(vma->vm_page_prot) =
 		pgprot_fb(pgprot_val(vma->vm_page_prot));
 
-	vma->vm_flags |= VM_IO | VM_RESERVED;
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
 
 	/* look for the starting tile */
 	tile = &gbe_tiles.cpu[offset >> TILE_SHIFT];

drivers/video/omap2/omapfb/omapfb-main.c

@@ -1128,7 +1128,7 @@ static int omapfb_mmap(struct fb_info *fbi, struct vm_area_struct *vma)
 	DBG("user mmap region start %lx, len %d, off %lx\n", start, len, off);
 
 	vma->vm_pgoff = off >> PAGE_SHIFT;
-	vma->vm_flags |= VM_IO | VM_RESERVED;
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
 	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 	vma->vm_ops = &mmap_user_ops;
 	vma->vm_private_data = rg;

drivers/video/sbuslib.c

@@ -57,9 +57,8 @@ int sbusfb_mmap_helper(struct sbus_mmap_map *map,
 
 	off = vma->vm_pgoff << PAGE_SHIFT;
 
-	/* To stop the swapper from even considering these pages */
-	vma->vm_flags |= (VM_IO | VM_RESERVED);
-	
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
+
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
 	/* Each page, see which map applies */

drivers/video/smscufx.c

@@ -803,7 +803,6 @@ static int ufx_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 			size = 0;
 	}
 
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
 	return 0;
 }
 

drivers/video/udlfb.c

@@ -345,7 +345,6 @@ static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 			size = 0;
 	}
 
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
 	return 0;
 }
 

drivers/video/vermilion/vermilion.c

@@ -1018,7 +1018,6 @@ static int vmlfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	offset += vinfo->vram_start;
 	pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
 	pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
-	vma->vm_flags |= VM_RESERVED | VM_IO;
 	if (remap_pfn_range(vma, vma->vm_start, offset >> PAGE_SHIFT,
 						size, vma->vm_page_prot))
 		return -EAGAIN;

drivers/video/vfb.c

@@ -439,7 +439,6 @@ static int vfb_mmap(struct fb_info *info,
 			size = 0;
 	}
 
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
 	return 0;
 
 }