[PATCH 4/6] mm: pass address down to rmap ones

Hugh Dickins
2009-11-10T22:00:41Z

KSM swapping will know where page_referenced_one() and try_to_unmap_one()
should look. It could hack page->index to get them to do what it wants,
but it seems cleaner now to pass the address down to them.

Make the same change to page_mkclean_one(), since it follows the same
pattern; but there's no real need in its case.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
---

mm/rmap.c | 53 ++++++++++++++++++++++++++--------------------------
1 file changed, 27 insertions(+), 26 deletions(-)

--- mm3/mm/rmap.c 2009-11-04 10:52:58.000000000 +0000
+++ mm4/mm/rmap.c 2009-11-04 10:53:05.000000000 +0000
@@ -336,21 +336,15 @@ int page_mapped_in_vma(struct page *page
* Subfunctions of page_referenced: page_referenced_one called
* repeatedly from either page_referenced_anon or page_referenced_file.
*/
-static int page_referenced_one(struct page *page,
- struct vm_area_struct *vma,
- unsigned int *mapcount,
+static int page_referenced_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address, unsigned int *mapcount,
unsigned long *vm_flags)
{
struct mm_struct *mm = vma->vm_mm;
- unsigned long address;
pte_t *pte;
spinlock_t *ptl;
int referenced = 0;

- address = vma_address(page, vma);
- if (address == -EFAULT)
- goto out;
-
pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
goto out;
@@ -408,6 +402,9 @@ static int page_referenced_anon(struct p

mapcount = page_mapcount(page);
list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
@@ -415,7 +412,7 @@ static int page_referenced_anon(struct p
*/
if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
continue;
- referenced += page_referenced_one(page, vma,
+ referenced += page_referenced_one(page, vma, address,
&mapcount, vm_flags);
if (!mapcount)
break;
@@ -473,6 +470,9 @@ static int page_referenced_file(struct p
mapcount = page_mapcount(page);

vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
@@ -480,7 +480,7 @@ static int page_referenced_file(struct p
*/
if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
continue;
- referenced += page_referenced_one(page, vma,
+ referenced += page_referenced_one(page, vma, address,
&mapcount, vm_flags);
if (!mapcount)
break;
@@ -534,18 +534,14 @@ int page_referenced(struct page *page,
return referenced;
}

-static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
+static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
+ unsigned long address)
{
struct mm_struct *mm = vma->vm_mm;
- unsigned long address;
pte_t *pte;
spinlock_t *ptl;
int ret = 0;

- address = vma_address(page, vma);
- if (address == -EFAULT)
- goto out;
-
pte = page_check_address(page, mm, address, &ptl, 1);
if (!pte)
goto out;
@@ -577,8 +573,12 @@ static int page_mkclean_file(struct addr

spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
- if (vma->vm_flags & VM_SHARED)
- ret += page_mkclean_one(page, vma);
+ if (vma->vm_flags & VM_SHARED) {
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret += page_mkclean_one(page, vma, address);
+ }
}
spin_unlock(&mapping->i_mmap_lock);
return ret;
@@ -760,19 +760,14 @@ void page_remove_rmap(struct page *page)
* repeatedly from either try_to_unmap_anon or try_to_unmap_file.
*/
static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
- enum ttu_flags flags)
+ unsigned long address, enum ttu_flags flags)
{
struct mm_struct *mm = vma->vm_mm;
- unsigned long address;
pte_t *pte;
pte_t pteval;
spinlock_t *ptl;
int ret = SWAP_AGAIN;

- address = vma_address(page, vma);
- if (address == -EFAULT)
- goto out;
-
pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
goto out;
@@ -1017,7 +1012,10 @@ static int try_to_unmap_anon(struct page
return ret;

list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
- ret = try_to_unmap_one(page, vma, flags);
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = try_to_unmap_one(page, vma, address, flags);
if (ret != SWAP_AGAIN || !page_mapped(page))
break;
}
@@ -1055,7 +1053,10 @@ static int try_to_unmap_file(struct page

spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
- ret = try_to_unmap_one(page, vma, flags);
+ unsigned long address = vma_address(page, vma);
+ if (address == -EFAULT)
+ continue;
+ ret = try_to_unmap_one(page, vma, address, flags);
if (ret != SWAP_AGAIN || !page_mapped(page))
goto out;
}