-/*
- * cgroup_attach_proc works in two stages, the first of which prefetches all
- * new css_sets needed (to make sure we have enough memory before committing
- * to the move) and stores them in a list of entries of the following type.
- * TODO: possible optimization: use css_set->rcu_head for chaining instead
- */
-struct cg_list_entry {
- struct css_set *cg;
- struct list_head links;
-};
-
-static bool css_set_check_fetched(struct cgroup *cgrp,
- struct task_struct *tsk, struct css_set *cg,
- struct list_head *newcg_list)
-{
- struct css_set *newcg;
- struct cg_list_entry *cg_entry;
- struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT];
-
- read_lock(&css_set_lock);
- newcg = find_existing_css_set(cg, cgrp, template);
- read_unlock(&css_set_lock);
-
- /* doesn't exist at all? */
- if (!newcg)
- return false;
- /* see if it's already in the list */
- list_for_each_entry(cg_entry, newcg_list, links)
- if (cg_entry->cg == newcg)
- return true;
-
- /* not found */
- return false;
-}
-
-/*
- * Find the new css_set and store it in the list in preparation for moving the
- * given task to the given cgroup. Returns 0 or -ENOMEM.
- */
-static int css_set_prefetch(struct cgroup *cgrp, struct css_set *cg,
- struct list_head *newcg_list)
-{
- struct css_set *newcg;
- struct cg_list_entry *cg_entry;
-
- /* ensure a new css_set will exist for this thread */
- newcg = find_css_set(cg, cgrp);
- if (!newcg)
- return -ENOMEM;
- /* add it to the list */
- cg_entry = kmalloc(sizeof(struct cg_list_entry), GFP_KERNEL);
- if (!cg_entry) {
- put_css_set(newcg);
- return -ENOMEM;
- }
- cg_entry->cg = newcg;
- list_add(&cg_entry->links, newcg_list);
- return 0;
-}
-