cgroups: Add an API to attach a task to current task's cgroup
Add a new kernel API to attach a task to current task's cgroup
in all the active hierarchies.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paul Menage <menage@google.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 0c62160..e0aa067 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -570,6 +570,7 @@
void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
int cgroup_scan_tasks(struct cgroup_scanner *scan);
int cgroup_attach_task(struct cgroup *, struct task_struct *);
+int cgroup_attach_task_current_cg(struct task_struct *);
/*
* CSS ID is ID for cgroup_subsys_state structs under subsys. This only works
@@ -626,6 +627,12 @@
return -EINVAL;
}
+/* No cgroups - nothing to do */
+static inline int cgroup_attach_task_current_cg(struct task_struct *t)
+{
+ return 0;
+}
+
#endif /* !CONFIG_CGROUPS */
#endif /* _LINUX_CGROUP_H */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 422cb19..37642ad 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1788,6 +1788,29 @@
return retval;
}
+/**
+ * cgroup_attach_task_current_cg - attach task 'tsk' to current task's cgroup
+ * @tsk: the task to be attached
+ */
+int cgroup_attach_task_current_cg(struct task_struct *tsk)
+{
+ struct cgroupfs_root *root;
+ struct cgroup *cur_cg;
+ int retval = 0;
+
+ cgroup_lock();
+ for_each_active_root(root) {
+ cur_cg = task_cgroup_from_root(current, root);
+ retval = cgroup_attach_task(cur_cg, tsk);
+ if (retval)
+ break;
+ }
+ cgroup_unlock();
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(cgroup_attach_task_current_cg);
+
/*
* Attach task with pid 'pid' to cgroup 'cgrp'. Call with cgroup_mutex
* held. May take task_lock of task