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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2012-10-08 16:28:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 16:22:17 +0900
commit4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1 (patch)
tree10200483a705005f41f543ed433581409cf2bf5f
parentcc2383ec06be093789469852e1fe96e1148e9a2c (diff)
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: 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>
-rw-r--r--include/linux/mm.h1
-rw-r--r--mm/huge_memory.c3
-rw-r--r--mm/ksm.c2
-rw-r--r--mm/memory.c14
-rw-r--r--mm/mmap.c2
5 files changed, 15 insertions, 7 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9c039f84b63..fb0685b1791 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -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 */
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 47206692cf8..9b72d127051 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1491,8 +1491,7 @@ out:
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)
diff --git a/mm/ksm.c b/mm/ksm.c
index d1cbe2aa6b3..f9ccb16559e 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -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 */
diff --git a/mm/memory.c b/mm/memory.c
index 655e1429388..7b1e4feaec0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -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 @@ out:
* 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);
diff --git a/mm/mmap.c b/mm/mmap.c
index 872441e8191..b0989f4d4f0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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? */