cgroup: remove cgrp->top_cgroup

It's not used, and it can be retrieved via cgrp->root->top_cgroup.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 9c300ad..64047ae 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -204,7 +204,6 @@ struct cgroup {
        struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
 
        struct cgroupfs_root *root;
-       struct cgroup *top_cgroup;
 
        /*
         * List of cg_cgroup_links pointing at css_sets with

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 6780459..c16719e 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1418,7 +1418,6 @@ static void init_cgroup_root(struct cgroupfs_root *root)
        root->number_of_cgroups = 1;
        cgrp->root = root;
        cgrp->name = &root_cgroup_name;
-       cgrp->top_cgroup = cgrp;
        init_cgroup_housekeeping(cgrp);
        list_add_tail(&cgrp->allcg_node, &root->allcg_list);
 }
@@ -4145,7 +4144,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 
        cgrp->parent = parent;
        cgrp->root = parent->root;
-       cgrp->top_cgroup = parent->top_cgroup;
 
        if (notify_on_release(parent))
                set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);