Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "This includes Roman's cgroup2 freezer implementation.

  It's a separate machanism from cgroup1 freezer. Instead of blocking
  user tasks in arbitrary uninterruptible sleeps, the new implementation
  extends jobctl stop - frozen tasks are trapped in jobctl stop until
  thawed and can be killed and ptraced. Lots of thanks to Oleg for
  sheperding the effort.

  Other than that, there are a few trivial changes"

* 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: never call do_group_exit() with task->frozen bit set
  kernel: cgroup: fix misuse of %x
  cgroup: get rid of cgroup_freezer_frozen_exit()
  cgroup: prevent spurious transition into non-frozen state
  cgroup: Remove unused cgrp variable
  cgroup: document cgroup v2 freezer interface
  cgroup: add tracing points for cgroup v2 freezer
  cgroup: make TRACE_CGROUP_PATH irq-safe
  kselftests: cgroup: add freezer controller self-tests
  kselftests: cgroup: don't fail on cg_kill_all() error in cg_destroy()
  cgroup: cgroup v2 freezer
  cgroup: protect cgroup->nr_(dying_)descendants by css_set_lock
  cgroup: implement __cgroup_task_count() helper
  cgroup: rename freezer.c into legacy_freezer.c
  cgroup: remove extra cgroup_migrate_finish() call

1 files changed, 43 insertions, 0 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 81f58b4a5418..c0077adeea83 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -881,4 +881,47 @@ static inline void put_cgroup_ns(struct cgroup_namespace *ns)
 		free_cgroup_ns(ns);
 }
 
+#ifdef CONFIG_CGROUPS
+
+void cgroup_enter_frozen(void);
+void cgroup_leave_frozen(bool always_leave);
+void cgroup_update_frozen(struct cgroup *cgrp);
+void cgroup_freeze(struct cgroup *cgrp, bool freeze);
+void cgroup_freezer_migrate_task(struct task_struct *task, struct cgroup *src,
+				 struct cgroup *dst);
+
+static inline bool cgroup_task_freeze(struct task_struct *task)
+{
+	bool ret;
+
+	if (task->flags & PF_KTHREAD)
+		return false;
+
+	rcu_read_lock();
+	ret = test_bit(CGRP_FREEZE, &task_dfl_cgroup(task)->flags);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static inline bool cgroup_task_frozen(struct task_struct *task)
+{
+	return task->frozen;
+}
+
+#else /* !CONFIG_CGROUPS */
+
+static inline void cgroup_enter_frozen(void) { }
+static inline void cgroup_leave_frozen(bool always_leave) { }
+static inline bool cgroup_task_freeze(struct task_struct *task)
+{
+	return false;
+}
+static inline bool cgroup_task_frozen(struct task_struct *task)
+{
+	return false;
+}
+
+#endif /* !CONFIG_CGROUPS */
+
 #endif /* _LINUX_CGROUP_H */