cgroup: add css_set->dfl_cgrp
To implement the unified hierarchy behavior, we'll need to be able to
determine the associated cgroup on the default hierarchy from css_set.
Let's add css_set->dfl_cgrp so that it can be accessed conveniently
and efficiently.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2a4f88d..c66bfc8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -651,6 +651,10 @@
struct cgrp_cset_link *link;
BUG_ON(list_empty(tmp_links));
+
+ if (cgroup_on_dfl(cgrp))
+ cset->dfl_cgrp = cgrp;
+
link = list_first_entry(tmp_links, struct cgrp_cset_link, cset_link);
link->cset = cset;
link->cgrp = cgrp;