diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 7251fc477a11835d9027c2da76d6250a9bb155ac..9c882f20803e06d5314682800c67f1e110772694 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -8,8 +8,6 @@
  */
 #include "sched.h"
 
-static DEFINE_SPINLOCK(sched_debug_lock);
-
 /*
  * This allows printing both to /proc/sched_debug and
  * to the console
@@ -476,16 +474,37 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
 #endif
 
 #ifdef CONFIG_CGROUP_SCHED
+static DEFINE_SPINLOCK(sched_debug_lock);
 static char group_path[PATH_MAX];
 
-static char *task_group_path(struct task_group *tg)
+static void task_group_path(struct task_group *tg, char *path, int plen)
 {
-	if (autogroup_path(tg, group_path, PATH_MAX))
-		return group_path;
+	if (autogroup_path(tg, path, plen))
+		return;
 
-	cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+	cgroup_path(tg->css.cgroup, path, plen);
+}
 
-	return group_path;
+/*
+ * Only 1 SEQ_printf_task_group_path() caller can use the full length
+ * group_path[] for cgroup path. Other simultaneous callers will have
+ * to use a shorter stack buffer. A "..." suffix is appended at the end
+ * of the stack buffer so that it will show up in case the output length
+ * matches the given buffer size to indicate possible path name truncation.
+ */
+#define SEQ_printf_task_group_path(m, tg, fmt...)			\
+{									\
+	if (spin_trylock(&sched_debug_lock)) {				\
+		task_group_path(tg, group_path, sizeof(group_path));	\
+		SEQ_printf(m, fmt, group_path);				\
+		spin_unlock(&sched_debug_lock);				\
+	} else {							\
+		char buf[128];						\
+		char *bufend = buf + sizeof(buf) - 3;			\
+		task_group_path(tg, buf, bufend - buf);			\
+		strcpy(bufend - 1, "...");				\
+		SEQ_printf(m, fmt, buf);				\
+	}								\
 }
 #endif
 
@@ -512,7 +531,7 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 	SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
 #endif
 #ifdef CONFIG_CGROUP_SCHED
-	SEQ_printf(m, " %s", task_group_path(task_group(p)));
+	SEQ_printf_task_group_path(m, task_group(p), " %s")
 #endif
 
 	SEQ_printf(m, "\n");
@@ -549,7 +568,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	SEQ_printf(m, "\n");
-	SEQ_printf(m, "cfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
+	SEQ_printf_task_group_path(m, cfs_rq->tg, "cfs_rq[%d]:%s\n", cpu);
 #else
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
@@ -620,7 +639,7 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
 	SEQ_printf(m, "\n");
-	SEQ_printf(m, "rt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
+	SEQ_printf_task_group_path(m, rt_rq->tg, "rt_rq[%d]:%s\n", cpu);
 #else
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, "rt_rq[%d]:\n", cpu);
@@ -672,7 +691,6 @@ void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
 static void print_cpu(struct seq_file *m, int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
-	unsigned long flags;
 
 #ifdef CONFIG_X86
 	{
@@ -723,13 +741,11 @@ do {									\
 	}
 #undef P
 
-	spin_lock_irqsave(&sched_debug_lock, flags);
 	print_cfs_stats(m, cpu);
 	print_rt_stats(m, cpu);
 	print_dl_stats(m, cpu);
 
 	print_rq(m, rq, cpu);
-	spin_unlock_irqrestore(&sched_debug_lock, flags);
 	SEQ_printf(m, "\n");
 }