cgroup: make cgroup_task_iter remember the cgroup being iterated

Currently all cgroup_task_iter functions require @cgrp to be passed
in, which is superflous and increases chance of usage error.  Make
cgroup_task_iter remember the cgroup being iterated and drop @cgrp
argument from next and end functions.

This patch doesn't introduce any behavior differences.

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, 6 insertions, 6 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index c9177f8fc661..e0ab9bfd679a 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -281,7 +281,7 @@ static void update_if_frozen(struct cgroup_subsys_state *css)
         /* are all tasks frozen? */
         cgroup_task_iter_start(css->cgroup, &it);
 
-        while ((task = cgroup_task_iter_next(css->cgroup, &it))) {
+        while ((task = cgroup_task_iter_next(&it))) {
                 if (freezing(task)) {
                         /*
                          * freezer_should_skip() indicates that the task
@@ -296,7 +296,7 @@ static void update_if_frozen(struct cgroup_subsys_state *css)
 
         freezer->state |= CGROUP_FROZEN;
 out_iter_end:
-        cgroup_task_iter_end(css->cgroup, &it);
+        cgroup_task_iter_end(&it);
 out_unlock:
         spin_unlock_irq(&freezer->lock);
 }
@@ -327,9 +327,9 @@ static void freeze_cgroup(struct freezer *freezer)
         struct task_struct *task;
 
         cgroup_task_iter_start(cgroup, &it);
-        while ((task = cgroup_task_iter_next(cgroup, &it)))
+        while ((task = cgroup_task_iter_next(&it)))
                 freeze_task(task);
-        cgroup_task_iter_end(cgroup, &it);
+        cgroup_task_iter_end(&it);
 }
 
 static void unfreeze_cgroup(struct freezer *freezer)
@@ -339,9 +339,9 @@ static void unfreeze_cgroup(struct freezer *freezer)
         struct task_struct *task;
 
         cgroup_task_iter_start(cgroup, &it);
-        while ((task = cgroup_task_iter_next(cgroup, &it)))
+        while ((task = cgroup_task_iter_next(&it)))
                 __thaw_task(task);
-        cgroup_task_iter_end(cgroup, &it);
+        cgroup_task_iter_end(&it);
 }
 
 /**