Merge branch 'stable/for-linus-fixes-3.3' of git://git.kernel.org/pub/scm/linux/kerne...

[cascardo/linux.git] / mm / ksm.c

diff --git a/mm/ksm.c b/mm/ksm.c
index 310544a..1925ffb 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -28,6 +28,7 @@
 #include <linux/kthread.h>
 #include <linux/wait.h>
 #include <linux/slab.h>
+#include <linux/memcontrol.h>
 #include <linux/rbtree.h>
 #include <linux/memory.h>
 #include <linux/mmu_notifier.h>
@@ -1571,6 +1572,16 @@ struct page *ksm_does_need_to_copy(struct page *page,
 
        new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
        if (new_page) {
+               /*
+                * The memcg-specific accounting when moving
+                * pages around the LRU lists relies on the
+                * page's owner (memcg) to be valid.  Usually,
+                * pages are assigned to a new owner before
+                * being put on the LRU list, but since this
+                * is not the case here, the stale owner from
+                * a previous allocation cycle must be reset.
+                */
+               mem_cgroup_reset_owner(new_page);
                copy_user_highpage(new_page, page, address, vma);
 
                SetPageDirty(new_page);