Commit a0a5a056 authored Aug 31, 2013 by Steven Rostedt (Red Hat) Committed by Steven Rostedt Sep 05, 2013

ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()



The function debug_lockdep_rcu_enabled() is part of the RCU lockdep
debugging, and is called very frequently. I found that if I enable
a lot of debugging and run the function graph tracer, this
function can cause a live lock of the system.

We don't usually trace lockdep infrastructure, no need to trace
this either.

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent af058ab0

kernel/rcupdate.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -122,7 +122,7 @@ struct lockdep_map rcu_sched_lock_map =
		STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
		EXPORT_SYMBOL_GPL(rcu_sched_lock_map);

		int debug_lockdep_rcu_enabled(void)
		int notrace debug_lockdep_rcu_enabled(void)
		{
		return rcu_scheduler_active && debug_locks &&
		current->lockdep_recursion == 0;