rcu: Dump only the current CPU's buffers for idle-entry/exit warnings

Problems in RCU idle entry and exit are almost always confined to the
offending CPU.  This commit therefore switches ftrace_dump() from
DUMP_ALL to DUMP_ORIG.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>

kernel/rcutree.c

@@ -358,7 +358,7 @@ static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval)
 		struct task_struct *idle = idle_task(smp_processor_id());
 
 		trace_rcu_dyntick("Error on entry: not idle task", oldval, 0);
-		ftrace_dump(DUMP_ALL);
+		ftrace_dump(DUMP_ORIG);
 		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
 			  current->pid, current->comm,
 			  idle->pid, idle->comm); /* must be idle task! */
@@ -468,7 +468,7 @@ static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval)
 
 		trace_rcu_dyntick("Error on exit: not idle task",
 				  oldval, rdtp->dynticks_nesting);
-		ftrace_dump(DUMP_ALL);
+		ftrace_dump(DUMP_ORIG);
 		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
 			  current->pid, current->comm,
 			  idle->pid, idle->comm); /* must be idle task! */