[PATCH rcu 09/12] refscale: Allow refscale without RCU Tasks Rude/Trace

["Paul E. McKenney" <paulmck@kernel.org>]

Currently, a CONFIG_PREEMPT_NONE=y kernel substitutes normal RCU for
RCU Tasks Rude and RCU Tasks Trace.  Unless that kernel builds refscale,
whether built-in or as a module, in which case these RCU Tasks flavors are
(unnecessarily) built in.  This both increases kernel size and increases
the complexity of certain tracing operations.  This commit therefore
decouples the presence of refscale from the presence of RCU Tasks Rude
and RCU Tasks Trace.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/Kconfig.debug                             |  2 --
 kernel/rcu/refscale.c                                | 12 +++++++++++-
 .../selftests/rcutorture/configs/refscale/CFcommon   |  2 ++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 454924e03ef3..dceaa3e754e5 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -63,8 +63,6 @@ config RCU_REF_SCALE_TEST
 	depends on DEBUG_KERNEL
 	select TORTURE_TEST
 	select SRCU
-	select TASKS_RUDE_RCU
-	select TASKS_TRACE_RCU
 	default n
 	help
 	  This option provides a kernel module that runs performance tests
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 5079e47b3d18..909644abee67 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -242,6 +242,8 @@ static struct ref_scale_ops rcu_tasks_ops = {
 
 #endif // #else // #ifdef CONFIG_TASKS_RCU
 
+#ifdef CONFIG_TASKS_TRACE_RCU
+
 // Definitions for RCU Tasks Trace ref scale testing.
 static void rcu_trace_ref_scale_read_section(const int nloops)
 {
@@ -271,6 +273,14 @@ static struct ref_scale_ops rcu_trace_ops = {
 	.name		= "rcu-trace"
 };
 
+#define RCU_TRACE_OPS &rcu_trace_ops,
+
+#else // #ifdef CONFIG_TASKS_TRACE_RCU
+
+#define RCU_TRACE_OPS
+
+#endif // #else // #ifdef CONFIG_TASKS_TRACE_RCU
+
 // Definitions for reference count
 static atomic_t refcnt;
 
@@ -800,7 +810,7 @@ ref_scale_init(void)
 	long i;
 	int firsterr = 0;
 	static struct ref_scale_ops *scale_ops[] = {
-		&rcu_ops, &srcu_ops, &rcu_trace_ops, RCU_TASKS_OPS &refcnt_ops, &rwlock_ops,
+		&rcu_ops, &srcu_ops, RCU_TRACE_OPS RCU_TASKS_OPS &refcnt_ops, &rwlock_ops,
 		&rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, &clock_ops,
 	};
 
diff --git a/tools/testing/selftests/rcutorture/configs/refscale/CFcommon b/tools/testing/selftests/rcutorture/configs/refscale/CFcommon
index 14fdafc576ce..fbea3b13baba 100644
--- a/tools/testing/selftests/rcutorture/configs/refscale/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/refscale/CFcommon
@@ -2,3 +2,5 @@ CONFIG_RCU_REF_SCALE_TEST=y
 CONFIG_PRINTK_TIME=y
 CONFIG_FORCE_TASKS_RCU=y
 #CHECK#CONFIG_TASKS_RCU=y
+CONFIG_FORCE_TASKS_TRACE_RCU=y
+#CHECK#CONFIG_TASKS_TRACE_RCU=y
-- 
2.31.1.189.g2e36527f23