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Commit 4b6e1e37 authored by Konstantin Khlebnikov's avatar Konstantin Khlebnikov Committed by Linus Torvalds
Browse files

mm: kill vma flag VM_INSERTPAGE 



Merge VM_INSERTPAGE into VM_MIXEDMAP.  VM_MIXEDMAP VMA can mix pure-pfn
ptes, special ptes and normal ptes.

Now copy_page_range() always copies VM_MIXEDMAP VMA on fork like
VM_PFNMAP.  If driver populates whole VMA at mmap() it probably not
expects page-faults.

This patch removes special check from vma_wants_writenotify() which
disables pages write tracking for VMA populated via vm_instert_page().
BDI below mapped file should not use dirty-accounting, moreover
do_wp_page() can handle this.

vm_insert_page() still marks vma after first usage.  Usually it is called
from f_op->mmap() handler under mm->mmap_sem write-lock, so it able to
change vma->vm_flags.  Caller must set VM_MIXEDMAP at mmap time if it
wants to call this function from other places, for example from page-fault
handler.

Signed-off-by: default avatarKonstantin 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc2383ec

include/linux/mm.h

+0 −1
Original line number Diff line number Diff line
@@ -103,7 +103,6 @@ extern unsigned int kobjsize(const void *objp); 
#define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */

#define VM_NONLINEAR	0x00800000	/* Is non-linear (remap_file_pages) */

#define VM_ARCH_1	0x01000000	/* Architecture-specific flag */

#define VM_INSERTPAGE	0x02000000	/* The vma has had "vm_insert_page()" done on it */

#define VM_NODUMP	0x04000000	/* Do not include in the core dump */



#define VM_CAN_NONLINEAR 0x08000000	/* Has ->fault & does nonlinear pages */

mm/huge_memory.c

+1 −2
Original line number Diff line number Diff line
@@ -1491,8 +1491,7 @@ int split_huge_page(struct page *page) 
	return ret;

}



#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP| \

		   VM_HUGETLB|VM_SHARED|VM_MAYSHARE)

#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE)



int hugepage_madvise(struct vm_area_struct *vma,

		     unsigned long *vm_flags, int advice)

mm/ksm.c

+1 −1
Original line number Diff line number Diff line
@@ -1469,7 +1469,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, 
		 */

		if (*vm_flags & (VM_MERGEABLE | VM_SHARED  | VM_MAYSHARE   |

				 VM_PFNMAP    | VM_IO      | VM_DONTEXPAND |

				 VM_RESERVED  | VM_HUGETLB | VM_INSERTPAGE |

				 VM_RESERVED  | VM_HUGETLB |

				 VM_NONLINEAR | VM_MIXEDMAP))

			return 0;		/* just ignore the advice */

mm/memory.c

+12 −2
Original line number Diff line number Diff line
@@ -1047,7 +1047,8 @@ 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_PFNMAP|VM_INSERTPAGE))) {

	if (!(vma->vm_flags & (VM_HUGETLB | VM_NONLINEAR |

			       VM_PFNMAP | VM_MIXEDMAP))) {

		if (!vma->anon_vma)

			return 0;

	}
@@ -2085,6 +2086,11 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, 
 * ask for a shared writable mapping!

 *

 * The page does not need to be reserved.

 *

 * Usually this function is called from f_op->mmap() handler

 * under mm->mmap_sem write-lock, so it can change vma->vm_flags.

 * Caller must set VM_MIXEDMAP on vma if it wants to call this

 * function from other places, for example from page-fault handler.

 */

int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,

			struct page *page)
@@ -2093,7 +2099,11 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 
		return -EFAULT;

	if (!page_count(page))

		return -EINVAL;

	vma->vm_flags |= VM_INSERTPAGE;

	if (!(vma->vm_flags & VM_MIXEDMAP)) {

		BUG_ON(down_read_trylock(&vma->vm_mm->mmap_sem));

		BUG_ON(vma->vm_flags & VM_PFNMAP);

		vma->vm_flags |= VM_MIXEDMAP;

	}

	return insert_page(vma, addr, page, vma->vm_page_prot);

}

EXPORT_SYMBOL(vm_insert_page);

mm/mmap.c

+1 −1
Original line number Diff line number Diff line
@@ -1190,7 +1190,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma) 
		return 0;



	/* Specialty mapping? */

	if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))

	if (vm_flags & VM_PFNMAP)

		return 0;



	/* Can the mapping track the dirty pages? */