rcu: Inline _rcu_barrier() into its sole remaining caller
Because rcu_barrier() is a one-line wrapper function for _rcu_barrier()
and because nothing else calls _rcu_barrier(), this commit inlines
_rcu_barrier() into rcu_barrier().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e140aaa..ce16b8d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2747,7 +2747,7 @@ static void rcu_leak_callback(struct rcu_head *rhp)
/*
* Helper function for call_rcu() and friends. The cpu argument will
* normally be -1, indicating "currently running CPU". It may specify
- * a CPU only if that CPU is a no-CBs CPU. Currently, only _rcu_barrier()
+ * a CPU only if that CPU is a no-CBs CPU. Currently, only rcu_barrier()
* is expected to specify a CPU.
*/
static void
@@ -2981,27 +2981,27 @@ static bool rcu_cpu_has_callbacks(bool *all_lazy)
}
/*
- * Helper function for _rcu_barrier() tracing. If tracing is disabled,
+ * Helper function for rcu_barrier() tracing. If tracing is disabled,
* the compiler is expected to optimize this away.
*/
-static void _rcu_barrier_trace(const char *s, int cpu, unsigned long done)
+static void rcu_barrier_trace(const char *s, int cpu, unsigned long done)
{
trace_rcu_barrier(rcu_state.name, s, cpu,
atomic_read(&rcu_state.barrier_cpu_count), done);
}
/*
- * RCU callback function for _rcu_barrier(). If we are last, wake
- * up the task executing _rcu_barrier().
+ * RCU callback function for rcu_barrier(). If we are last, wake
+ * up the task executing rcu_barrier().
*/
static void rcu_barrier_callback(struct rcu_head *rhp)
{
if (atomic_dec_and_test(&rcu_state.barrier_cpu_count)) {
- _rcu_barrier_trace(TPS("LastCB"), -1,
+ rcu_barrier_trace(TPS("LastCB"), -1,
rcu_state.barrier_sequence);
complete(&rcu_state.barrier_completion);
} else {
- _rcu_barrier_trace(TPS("CB"), -1, rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("CB"), -1, rcu_state.barrier_sequence);
}
}
@@ -3012,33 +3012,40 @@ static void rcu_barrier_func(void *unused)
{
struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);
- _rcu_barrier_trace(TPS("IRQ"), -1, rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("IRQ"), -1, rcu_state.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(&rcu_state.barrier_cpu_count);
} else {
debug_rcu_head_unqueue(&rdp->barrier_head);
- _rcu_barrier_trace(TPS("IRQNQ"), -1,
+ rcu_barrier_trace(TPS("IRQNQ"), -1,
rcu_state.barrier_sequence);
}
}
-/* Orchestrate an RCU barrier, waiting for all RCU callbacks to complete. */
-static void _rcu_barrier(void)
+/**
+ * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
+ *
+ * Note that this primitive does not necessarily wait for an RCU grace period
+ * to complete. For example, if there are no RCU callbacks queued anywhere
+ * in the system, then rcu_barrier() is within its rights to return
+ * immediately, without waiting for anything, much less an RCU grace period.
+ */
+void rcu_barrier(void)
{
int cpu;
struct rcu_data *rdp;
unsigned long s = rcu_seq_snap(&rcu_state.barrier_sequence);
- _rcu_barrier_trace(TPS("Begin"), -1, s);
+ rcu_barrier_trace(TPS("Begin"), -1, s);
/* Take mutex to serialize concurrent rcu_barrier() requests. */
mutex_lock(&rcu_state.barrier_mutex);
/* Did someone else do our work for us? */
if (rcu_seq_done(&rcu_state.barrier_sequence, s)) {
- _rcu_barrier_trace(TPS("EarlyExit"), -1,
+ rcu_barrier_trace(TPS("EarlyExit"), -1,
rcu_state.barrier_sequence);
smp_mb(); /* caller's subsequent code after above check. */
mutex_unlock(&rcu_state.barrier_mutex);
@@ -3047,7 +3054,7 @@ static void _rcu_barrier(void)
/* Mark the start of the barrier operation. */
rcu_seq_start(&rcu_state.barrier_sequence);
- _rcu_barrier_trace(TPS("Inc1"), -1, rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("Inc1"), -1, rcu_state.barrier_sequence);
/*
* Initialize the count to one rather than to zero in order to
@@ -3070,10 +3077,10 @@ static void _rcu_barrier(void)
rdp = per_cpu_ptr(&rcu_data, cpu);
if (rcu_is_nocb_cpu(cpu)) {
if (!rcu_nocb_cpu_needs_barrier(cpu)) {
- _rcu_barrier_trace(TPS("OfflineNoCB"), cpu,
+ rcu_barrier_trace(TPS("OfflineNoCB"), cpu,
rcu_state.barrier_sequence);
} else {
- _rcu_barrier_trace(TPS("OnlineNoCB"), cpu,
+ rcu_barrier_trace(TPS("OnlineNoCB"), cpu,
rcu_state.barrier_sequence);
smp_mb__before_atomic();
atomic_inc(&rcu_state.barrier_cpu_count);
@@ -3081,11 +3088,11 @@ static void _rcu_barrier(void)
rcu_barrier_callback, cpu, 0);
}
} else if (rcu_segcblist_n_cbs(&rdp->cblist)) {
- _rcu_barrier_trace(TPS("OnlineQ"), cpu,
+ rcu_barrier_trace(TPS("OnlineQ"), cpu,
rcu_state.barrier_sequence);
smp_call_function_single(cpu, rcu_barrier_func, NULL, 1);
} else {
- _rcu_barrier_trace(TPS("OnlineNQ"), cpu,
+ rcu_barrier_trace(TPS("OnlineNQ"), cpu,
rcu_state.barrier_sequence);
}
}
@@ -3102,25 +3109,12 @@ static void _rcu_barrier(void)
wait_for_completion(&rcu_state.barrier_completion);
/* Mark the end of the barrier operation. */
- _rcu_barrier_trace(TPS("Inc2"), -1, rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("Inc2"), -1, rcu_state.barrier_sequence);
rcu_seq_end(&rcu_state.barrier_sequence);
/* Other rcu_barrier() invocations can now safely proceed. */
mutex_unlock(&rcu_state.barrier_mutex);
}
-
-/**
- * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
- *
- * Note that this primitive does not necessarily wait for an RCU grace period
- * to complete. For example, if there are no RCU callbacks queued anywhere
- * in the system, then rcu_barrier() is within its rights to return
- * immediately, without waiting for anything, much less an RCU grace period.
- */
-void rcu_barrier(void)
-{
- _rcu_barrier();
-}
EXPORT_SYMBOL_GPL(rcu_barrier);
/*
