* task->alloc_lock (inside __thaw_task(), prevents race with refrigerator())
* sighand->siglock
*/
-static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
- struct cgroup *cgroup)
+static struct cgroup_subsys_state *freezer_create(struct cgroup *cgroup)
{
struct freezer *freezer;
return &freezer->css;
}
-static void freezer_destroy(struct cgroup_subsys *ss,
- struct cgroup *cgroup)
+static void freezer_destroy(struct cgroup *cgroup)
{
- kfree(cgroup_freezer(cgroup));
+ struct freezer *freezer = cgroup_freezer(cgroup);
+
+ if (freezer->state != CGROUP_THAWED)
+ atomic_dec(&system_freezing_cnt);
+ kfree(freezer);
+}
+
+/* task is frozen or will freeze immediately when next it gets woken */
+static bool is_task_frozen_enough(struct task_struct *task)
+{
+ return frozen(task) ||
+ (task_is_stopped_or_traced(task) && freezing(task));
}
/*
* a write to that file racing against an attach, and hence the
* can_attach() result will remain valid until the attach completes.
*/
-static int freezer_can_attach(struct cgroup_subsys *ss,
- struct cgroup *new_cgroup,
- struct task_struct *task)
+static int freezer_can_attach(struct cgroup *new_cgroup,
+ 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)
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)
+static void freezer_fork(struct task_struct *task)
{
struct freezer *freezer;
/* Locking avoids race with FREEZING -> THAWED transitions. */
if (freezer->state == CGROUP_FREEZING)
- freeze_task(task, true);
+ freeze_task(task);
spin_unlock_irq(&freezer->lock);
}
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
ntotal++;
- if (freezing(task) && frozen(task))
+ if (freezing(task) && is_task_frozen_enough(task))
nfrozen++;
}
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
- if (!freeze_task(task, true))
+ if (!freeze_task(task))
continue;
- if (frozen(task))
+ if (is_task_frozen_enough(task))
continue;
if (!freezing(task) && !freezer_should_skip(task))
num_cant_freeze_now++;
switch (goal_state) {
case CGROUP_THAWED:
+ if (freezer->state != CGROUP_THAWED)
+ atomic_dec(&system_freezing_cnt);
freezer->state = CGROUP_THAWED;
unfreeze_cgroup(cgroup, freezer);
break;
case CGROUP_FROZEN:
+ if (freezer->state == CGROUP_THAWED)
+ atomic_inc(&system_freezing_cnt);
freezer->state = CGROUP_FREEZING;
retval = try_to_freeze_cgroup(cgroup, freezer);
break;
.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,
};