sched: add uid information to sched_debug for CONFIG_USER_SCHED

Impact: extend information in /proc/sched_debug

This patch adds uid information in sched_debug for CONFIG_USER_SCHED
Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/sched.h

@@ -2218,6 +2218,7 @@ extern void normalize_rt_tasks(void);
 extern struct task_group init_task_group;
 #ifdef CONFIG_USER_SCHED
 extern struct task_group root_task_group;
+extern void set_tg_uid(struct user_struct *user);
 #endif
 
 extern struct task_group *sched_create_group(struct task_group *parent);

kernel/sched.c

@@ -261,6 +261,10 @@ struct task_group {
 	struct cgroup_subsys_state css;
 #endif
 
+#ifdef CONFIG_USER_SCHED
+	uid_t uid;
+#endif
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	/* schedulable entities of this group on each cpu */
 	struct sched_entity **se;
@@ -286,6 +290,12 @@ struct task_group {
 
 #ifdef CONFIG_USER_SCHED
 
+/* Helper function to pass uid information to create_sched_user() */
+void set_tg_uid(struct user_struct *user)
+{
+	user->tg->uid = user->uid;
+}
+
 /*
  * Root task group.
  * 	Every UID task group (including init_task_group aka UID-0) will

kernel/sched_debug.c

@@ -160,10 +160,14 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	cgroup_path(tg->css.cgroup, path, sizeof(path));
 
 	SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, path);
+#elif defined(CONFIG_USER_SCHED) && defined(CONFIG_FAIR_GROUP_SCHED)
+	{
+		uid_t uid = cfs_rq->tg->uid;
+		SEQ_printf(m, "\ncfs_rq[%d] for UID: %u\n", cpu, uid);
+	}
 #else
 	SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
 #endif
-
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
 			SPLIT_NS(cfs_rq->exec_clock));
 

kernel/user.c

@@ -101,6 +101,8 @@ static int sched_create_user(struct user_struct *up)
 	if (IS_ERR(up->tg))
 		rc = -ENOMEM;
 
+	set_tg_uid(up);
+
 	return rc;
 }