This patch changes placement of mem_cgroup_uncharge_cache_page().
After this patch, mem_cgroup_uncharge_cache_page() is called only after
page->mapping is cleared. This will make uncharge() handling easier in future.
(And error check code is added.)
Signed-off-by: KAMEZAWA Hiruyoki <kamezawa.hiroyu@jp.fujitsu.com>
mm/filemap.c | 2 +-
mm/memcontrol.c | 1 +
mm/migrate.c | 13 ++++++++++---
3 files changed, 12 insertions(+), 4 deletions(-)
Index: linux-2.6.27-rc1-mm1/mm/filemap.c
===================================================================
--- linux-2.6.27-rc1-mm1.orig/mm/filemap.c
+++ linux-2.6.27-rc1-mm1/mm/filemap.c
@@ -116,12 +116,12 @@ void __remove_from_page_cache(struct pag
{
struct address_space *mapping = page->mapping;
- mem_cgroup_uncharge_cache_page(page);
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
BUG_ON(page_mapped(page));
+ mem_cgroup_uncharge_cache_page(page);
/*
* Some filesystems seem to re-dirty the page even after
Index: linux-2.6.27-rc1-mm1/mm/migrate.c
===================================================================
--- linux-2.6.27-rc1-mm1.orig/mm/migrate.c
+++ linux-2.6.27-rc1-mm1/mm/migrate.c
@@ -330,8 +330,6 @@ static int migrate_page_move_mapping(str
__inc_zone_page_state(newpage, NR_FILE_PAGES);
spin_unlock_irq(&mapping->tree_lock);
- if (!PageSwapCache(newpage))
- mem_cgroup_uncharge_cache_page(page);
return 0;
}
@@ -378,7 +376,16 @@ static void migrate_page_copy(struct pag
#endif
ClearPagePrivate(page);
set_page_private(page, 0);
- page->mapping = NULL;
+
+ /* PageAnon() checks page->mapping's bit */
+ if (PageAnon(page)) {
+ /* This page is uncharged in try_to_unmap() */
+ page->mapping = NULL;
+ } else {
+ /* This page was removed from radix-tree.*/
+ page->mapping = NULL;
+ mem_cgroup_uncharge_cache_page(page);
+ }
/*
* If any waiters have accumulated on the new page then
Index: linux-2.6.27-rc1-mm1/mm/memcontrol.c
===================================================================
--- linux-2.6.27-rc1-mm1.orig/mm/memcontrol.c
+++ linux-2.6.27-rc1-mm1/mm/memcontrol.c
@@ -804,6 +804,7 @@ void mem_cgroup_uncharge_page(struct pag
void mem_cgroup_uncharge_cache_page(struct page *page)
{
VM_BUG_ON(page_mapped(page));
+ VM_BUG_ON(page->mapping);
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
}
--
