THP: fix comment about memory barrier

[mirror_ubuntu-zesty-kernel.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index ba94dec5b25900e47093544e11f8c765bf243f9d..f7a1fba85d140483242345e97acdbdf62eaafda8 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3244,6 +3244,11 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
        page = alloc_zeroed_user_highpage_movable(vma, address);
        if (!page)
                goto oom;
+       /*
+        * The memory barrier inside __SetPageUptodate makes sure that
+        * preceeding stores to the page contents become visible before
+        * the set_pte_at() write.
+        */
        __SetPageUptodate(page);
 
        if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))