cgroup: rename cgroup_iter to cgroup_task_iter

cgroup now has multiple iterators and it's quite confusing to have
something which walks over tasks of a single cgroup named cgroup_iter.
Let's rename it to cgroup_task_iter.

While at it, reformat / update comments and replace the overview
comment above the interface function decls with proper function
comments.  Such overview can be useful but function comments should be
more than enough here.

This is pure rename and doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>

1 files changed, 8 insertions, 23 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 4bc22f4a1abb..ea439794bd9b 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -889,31 +889,16 @@ css_next_descendant_post(struct cgroup_subsys_state *pos,
 	for ((pos) = css_next_descendant_post(NULL, (css)); (pos);	\
 	     (pos) = css_next_descendant_post((pos), (css)))
 
-/* A cgroup_iter should be treated as an opaque object */
-struct cgroup_iter {
-	struct list_head *cset_link;
-	struct list_head *task;
+/* A cgroup_task_iter should be treated as an opaque object */
+struct cgroup_task_iter {
+	struct list_head		*cset_link;
+	struct list_head		*task;
 };
 
-/*
- * To iterate across the tasks in a cgroup:
- *
- * 1) call cgroup_iter_start to initialize an iterator
- *
- * 2) call cgroup_iter_next() to retrieve member tasks until it
- *    returns NULL or until you want to end the iteration
- *
- * 3) call cgroup_iter_end() to destroy the iterator.
- *
- * Or, call cgroup_scan_tasks() to iterate through every task in a
- * cgroup - cgroup_scan_tasks() holds the css_set_lock when calling
- * the test_task() callback, but not while calling the process_task()
- * callback.
- */
-void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it);
-struct task_struct *cgroup_iter_next(struct cgroup *cgrp,
-					struct cgroup_iter *it);
-void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
+void cgroup_task_iter_start(struct cgroup *cgrp, struct cgroup_task_iter *it);
+struct task_struct *cgroup_task_iter_next(struct cgroup *cgrp,
+					  struct cgroup_task_iter *it);
+void cgroup_task_iter_end(struct cgroup *cgrp, struct cgroup_task_iter *it);
 int cgroup_scan_tasks(struct cgroup_scanner *scan);
 int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
 int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);