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authorRik van Riel <riel@redhat.com>2010-08-09 17:19:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-09 20:45:02 -0700
commitad8c2ee801ad7a52d919b478d9b2c7b39a72d295 (patch)
treebc56cc023da3467447b0aecd30c0516881d53992 /mm
parent51b1bd2ace1595b72956224deda349efa880b693 (diff)
rmap: add exclusive page to private anon_vma on swapin
On swapin it is fairly common for a page to be owned exclusively by one process. In that case we want to add the page to the anon_vma of that process's VMA, instead of to the root anon_vma. This will reduce the amount of rmap searching that the swapout code needs to do. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c4
-rw-r--r--mm/rmap.c13
2 files changed, 15 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 6b0c37dcfd1..6bc039486e9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2628,6 +2628,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
swp_entry_t entry;
pte_t pte;
struct mem_cgroup *ptr = NULL;
+ int exclusive = 0;
int ret = 0;
if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
@@ -2722,10 +2723,11 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
flags &= ~FAULT_FLAG_WRITE;
+ exclusive = 1;
}
flush_icache_page(vma, page);
set_pte_at(mm, address, page_table, pte);
- page_add_anon_rmap(page, vma, address);
+ do_page_add_anon_rmap(page, vma, address, exclusive);
/* It's better to call commit-charge after rmap is established */
mem_cgroup_commit_charge_swapin(page, ptr);
diff --git a/mm/rmap.c b/mm/rmap.c
index 4d152a6d3a8..a7d0f548263 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -830,6 +830,17 @@ static void __page_check_anon_rmap(struct page *page,
void page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address)
{
+ do_page_add_anon_rmap(page, vma, address, 0);
+}
+
+/*
+ * Special version of the above for do_swap_page, which often runs
+ * into pages that are exclusively owned by the current process.
+ * Everybody else should continue to use page_add_anon_rmap above.
+ */
+void do_page_add_anon_rmap(struct page *page,
+ struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
int first = atomic_inc_and_test(&page->_mapcount);
if (first)
__inc_zone_page_state(page, NR_ANON_PAGES);
@@ -839,7 +850,7 @@ void page_add_anon_rmap(struct page *page,
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
if (first)
- __page_set_anon_rmap(page, vma, address, 0);
+ __page_set_anon_rmap(page, vma, address, exclusive);
else
__page_check_anon_rmap(page, vma, address);
}