Commit 2053937a authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony)
Browse files

rcu: Add a trace event for synchronize_rcu_normal() 



Add an rcu_sr_normal() trace event. It takes three arguments
first one is the name of RCU flavour, second one is a user id
which triggeres synchronize_rcu_normal() and last one is an
event.

There are two traces in the synchronize_rcu_normal(). On entry,
when a new request is registered and on exit point when request
is completed.

Please note, CONFIG_RCU_TRACE=y is required to activate traces.

Reviewed-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
parent 988f569a

include/trace/events/rcu.h

+27 −0
Original line number Diff line number Diff line
@@ -707,6 +707,33 @@ TRACE_EVENT_RCU(rcu_invoke_kfree_bulk_callback, 
		__entry->rcuname, __entry->p, __entry->nr_records)

);



/*

 * Tracepoint for a normal synchronize_rcu() states. The first argument

 * is the RCU flavor, the second argument is a pointer to rcu_head the

 * last one is an event.

 */

TRACE_EVENT_RCU(rcu_sr_normal,



	TP_PROTO(const char *rcuname, struct rcu_head *rhp, const char *srevent),



	TP_ARGS(rcuname, rhp, srevent),



	TP_STRUCT__entry(

		__field(const char *, rcuname)

		__field(void *, rhp)

		__field(const char *, srevent)

	),



	TP_fast_assign(

		__entry->rcuname = rcuname;

		__entry->rhp = rhp;

		__entry->srevent = srevent;

	),



	TP_printk("%s rhp=0x%p event=%s",

		__entry->rcuname, __entry->rhp, __entry->srevent)

);



/*

 * Tracepoint for exiting rcu_do_batch after RCU callbacks have been

 * invoked.  The first argument is the name of the RCU flavor,

kernel/rcu/tree.c

+6 −1
Original line number Diff line number Diff line
@@ -3863,9 +3863,11 @@ static void synchronize_rcu_normal(void) 
{

	struct rcu_synchronize rs;



	trace_rcu_sr_normal(rcu_state.name, &rs.head, TPS("request"));



	if (!READ_ONCE(rcu_normal_wake_from_gp)) {

		wait_rcu_gp(call_rcu_hurry);

		return;

		goto trace_complete_out;

	}



	init_rcu_head_on_stack(&rs.head);
@@ -3886,6 +3888,9 @@ static void synchronize_rcu_normal(void) 
	/* Now we can wait. */

	wait_for_completion(&rs.completion);

	destroy_rcu_head_on_stack(&rs.head);



trace_complete_out:

	trace_rcu_sr_normal(rcu_state.name, &rs.head, TPS("complete"));

}



/**