1 files changed, 25 insertions, 3 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1b7f9d525013..34256ad9e553 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -457,6 +457,28 @@ void cgroup_exclude_rmdir(struct cgroup_subsys_state *css);
 void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css);
 
 /*
+ * Control Group taskset, used to pass around set of tasks to cgroup_subsys
+ * methods.
+ */
+struct cgroup_taskset;
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
+struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset);
+int cgroup_taskset_size(struct cgroup_taskset *tset);
+
+/**
+ * cgroup_taskset_for_each - iterate cgroup_taskset
+ * @task: the loop cursor
+ * @skip_cgrp: skip if task's cgroup matches this, %NULL to iterate through all
+ * @tset: taskset to iterate
+ */
+#define cgroup_taskset_for_each(task, skip_cgrp, tset)                  \
+        for ((task) = cgroup_taskset_first((tset)); (task);             \
+             (task) = cgroup_taskset_next((tset)))                      \
+                if (!(skip_cgrp) ||                                     \
+                    cgroup_taskset_cur_cgroup((tset)) != (skip_cgrp))
+
+/*
  * Control Group subsystem type.
  * See Documentation/cgroups/cgroups.txt for details
  */
@@ -467,14 +489,14 @@ struct cgroup_subsys {
         int (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
         void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
         int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                          struct task_struct *tsk);
+                          struct cgroup_taskset *tset);
         int (*can_attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
         void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                              struct task_struct *tsk);
+                              struct cgroup_taskset *tset);
         void (*pre_attach)(struct cgroup *cgrp);
         void (*attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
         void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                       struct cgroup *old_cgrp, struct task_struct *tsk);
+                       struct cgroup_taskset *tset);
         void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);
         void (*exit)(struct cgroup_subsys *ss, struct cgroup *cgrp,
                         struct cgroup *old_cgrp, struct task_struct *task);