hugetlb/cgroup: migrate hugetlb cgroup info from oldpage to new page during migration

[firefly-linux-kernel-4.4.55.git] / mm / hugetlb_cgroup.c

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index d1ca1196e62ffd577057a04b5ab02cabc3264634..680e4819e0775ed50bdb7e928b62cf44a9d005aa 100644 (file)
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -386,6 +386,26 @@ int __init hugetlb_cgroup_file_init(int idx)
        return 0;
 }
 
+void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
+{
+       struct hugetlb_cgroup *h_cg;
+
+       if (hugetlb_cgroup_disabled())
+               return;
+
+       VM_BUG_ON(!PageHuge(oldhpage));
+       spin_lock(&hugetlb_lock);
+       h_cg = hugetlb_cgroup_from_page(oldhpage);
+       set_hugetlb_cgroup(oldhpage, NULL);
+       cgroup_exclude_rmdir(&h_cg->css);
+
+       /* move the h_cg details to new cgroup */
+       set_hugetlb_cgroup(newhpage, h_cg);
+       spin_unlock(&hugetlb_lock);
+       cgroup_release_and_wakeup_rmdir(&h_cg->css);
+       return;
+}
+
 struct cgroup_subsys hugetlb_subsys = {
        .name = "hugetlb",
        .create     = hugetlb_cgroup_create,