Commit 8344b871 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove rsp parameter from _rcu_barrier() and friends 



There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
_rcu_barrier_trace() and _rcu_barrier().

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 98ece508

kernel/rcu/tree.c

+19 −22
Original line number Diff line number Diff line
@@ -3156,11 +3156,10 @@ static bool rcu_cpu_has_callbacks(bool *all_lazy) 
 * Helper function for _rcu_barrier() tracing.  If tracing is disabled,

 * the compiler is expected to optimize this away.

 */

static void _rcu_barrier_trace(struct rcu_state *rsp, const char *s,

			       int cpu, unsigned long done)

static void _rcu_barrier_trace(const char *s, int cpu, unsigned long done)

{

	trace_rcu_barrier(rsp->name, s, cpu,

			  atomic_read(&rsp->barrier_cpu_count), done);

	trace_rcu_barrier(rcu_state.name, s, cpu,

			  atomic_read(&rcu_state.barrier_cpu_count), done);

}



/*
@@ -3173,11 +3172,10 @@ static void rcu_barrier_callback(struct rcu_head *rhp) 
	struct rcu_state *rsp = rdp->rsp;



	if (atomic_dec_and_test(&rsp->barrier_cpu_count)) {

		_rcu_barrier_trace(rsp, TPS("LastCB"), -1,

				   rsp->barrier_sequence);

		_rcu_barrier_trace(TPS("LastCB"), -1, rsp->barrier_sequence);

		complete(&rsp->barrier_completion);

	} else {

		_rcu_barrier_trace(rsp, TPS("CB"), -1, rsp->barrier_sequence);

		_rcu_barrier_trace(TPS("CB"), -1, rsp->barrier_sequence);

	}

}
@@ -3189,15 +3187,14 @@ static void rcu_barrier_func(void *type) 
	struct rcu_state *rsp = type;

	struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);



	_rcu_barrier_trace(rsp, TPS("IRQ"), -1, rsp->barrier_sequence);

	_rcu_barrier_trace(TPS("IRQ"), -1, rsp->barrier_sequence);

	rdp->barrier_head.func = rcu_barrier_callback;

	debug_rcu_head_queue(&rdp->barrier_head);

	if (rcu_segcblist_entrain(&rdp->cblist, &rdp->barrier_head, 0)) {

		atomic_inc(&rsp->barrier_cpu_count);

	} else {

		debug_rcu_head_unqueue(&rdp->barrier_head);

		_rcu_barrier_trace(rsp, TPS("IRQNQ"), -1,

				   rsp->barrier_sequence);

		_rcu_barrier_trace(TPS("IRQNQ"), -1, rsp->barrier_sequence);

	}

}
@@ -3205,21 +3202,21 @@ static void rcu_barrier_func(void *type) 
 * Orchestrate the specified type of RCU barrier, waiting for all

 * RCU callbacks of the specified type to complete.

 */

static void _rcu_barrier(struct rcu_state *rsp)

static void _rcu_barrier(void)

{

	int cpu;

	struct rcu_data *rdp;

	struct rcu_state *rsp = &rcu_state;

	unsigned long s = rcu_seq_snap(&rsp->barrier_sequence);



	_rcu_barrier_trace(rsp, TPS("Begin"), -1, s);

	_rcu_barrier_trace(TPS("Begin"), -1, s);



	/* Take mutex to serialize concurrent rcu_barrier() requests. */

	mutex_lock(&rsp->barrier_mutex);



	/* Did someone else do our work for us? */

	if (rcu_seq_done(&rsp->barrier_sequence, s)) {

		_rcu_barrier_trace(rsp, TPS("EarlyExit"), -1,

				   rsp->barrier_sequence);

		_rcu_barrier_trace(TPS("EarlyExit"), -1, rsp->barrier_sequence);

		smp_mb(); /* caller's subsequent code after above check. */

		mutex_unlock(&rsp->barrier_mutex);

		return;
@@ -3227,7 +3224,7 @@ static void _rcu_barrier(struct rcu_state *rsp) 


	/* Mark the start of the barrier operation. */

	rcu_seq_start(&rsp->barrier_sequence);

	_rcu_barrier_trace(rsp, TPS("Inc1"), -1, rsp->barrier_sequence);

	_rcu_barrier_trace(TPS("Inc1"), -1, rsp->barrier_sequence);



	/*

	 * Initialize the count to one rather than to zero in order to
@@ -3250,10 +3247,10 @@ static void _rcu_barrier(struct rcu_state *rsp) 
		rdp = per_cpu_ptr(&rcu_data, cpu);

		if (rcu_is_nocb_cpu(cpu)) {

			if (!rcu_nocb_cpu_needs_barrier(rsp, cpu)) {

				_rcu_barrier_trace(rsp, TPS("OfflineNoCB"), cpu,

				_rcu_barrier_trace(TPS("OfflineNoCB"), cpu,

						   rsp->barrier_sequence);

			} else {

				_rcu_barrier_trace(rsp, TPS("OnlineNoCB"), cpu,

				_rcu_barrier_trace(TPS("OnlineNoCB"), cpu,

						   rsp->barrier_sequence);

				smp_mb__before_atomic();

				atomic_inc(&rsp->barrier_cpu_count);
@@ -3261,11 +3258,11 @@ static void _rcu_barrier(struct rcu_state *rsp) 
					   rcu_barrier_callback, cpu, 0);

			}

		} else if (rcu_segcblist_n_cbs(&rdp->cblist)) {

			_rcu_barrier_trace(rsp, TPS("OnlineQ"), cpu,

			_rcu_barrier_trace(TPS("OnlineQ"), cpu,

					   rsp->barrier_sequence);

			smp_call_function_single(cpu, rcu_barrier_func, rsp, 1);

		} else {

			_rcu_barrier_trace(rsp, TPS("OnlineNQ"), cpu,

			_rcu_barrier_trace(TPS("OnlineNQ"), cpu,

					   rsp->barrier_sequence);

		}

	}
@@ -3282,7 +3279,7 @@ static void _rcu_barrier(struct rcu_state *rsp) 
	wait_for_completion(&rsp->barrier_completion);



	/* Mark the end of the barrier operation. */

	_rcu_barrier_trace(rsp, TPS("Inc2"), -1, rsp->barrier_sequence);

	_rcu_barrier_trace(TPS("Inc2"), -1, rsp->barrier_sequence);

	rcu_seq_end(&rsp->barrier_sequence);



	/* Other rcu_barrier() invocations can now safely proceed. */
@@ -3294,7 +3291,7 @@ static void _rcu_barrier(struct rcu_state *rsp) 
 */

void rcu_barrier_bh(void)

{

	_rcu_barrier(&rcu_state);

	_rcu_barrier();

}

EXPORT_SYMBOL_GPL(rcu_barrier_bh);
@@ -3308,7 +3305,7 @@ EXPORT_SYMBOL_GPL(rcu_barrier_bh); 
 */

void rcu_barrier(void)

{

	_rcu_barrier(&rcu_state);

	_rcu_barrier();

}

EXPORT_SYMBOL_GPL(rcu_barrier);