cgroup: don't use subsys->can_attach_task() or ->attach_task()
Now that subsys->can_attach() and attach() take @tset instead of
@task, they can handle per-task operations. Convert
->can_attach_task() and ->attach_task() users to use ->can_attach()
and attach() instead. Most converions are straight-forward.
Noteworthy changes are,
* In cgroup_freezer, remove unnecessary NULL assignments to unused
methods. It's useless and very prone to get out of sync, which
already happened.
* In cpuset, PF_THREAD_BOUND test is checked for each task. This
doesn't make any practical difference but is conceptually cleaner.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index e95c6fb..0e74805 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -162,10 +162,14 @@
struct cgroup_taskset *tset)
{
struct freezer *freezer;
+ struct task_struct *task;
/*
* Anything frozen can't move or be moved to/from.
*/
+ cgroup_taskset_for_each(task, new_cgroup, tset)
+ if (cgroup_freezing(task))
+ return -EBUSY;
freezer = cgroup_freezer(new_cgroup);
if (freezer->state != CGROUP_THAWED)
@@ -174,11 +178,6 @@
return 0;
}
-static int freezer_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
-{
- return cgroup_freezing(tsk) ? -EBUSY : 0;
-}
-
static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
{
struct freezer *freezer;
@@ -374,10 +373,5 @@
.populate = freezer_populate,
.subsys_id = freezer_subsys_id,
.can_attach = freezer_can_attach,
- .can_attach_task = freezer_can_attach_task,
- .pre_attach = NULL,
- .attach_task = NULL,
- .attach = NULL,
.fork = freezer_fork,
- .exit = NULL,
};