From: Paul E. McKenney <paulmck@kernel.org>
Date: Fri, 25 Mar 2022 23:39:01 +0000 (-0700)
Subject: rcuscale: Allow rcuscale without RCU Tasks
X-Git-Tag: v5.19-rc1~252^2~1^7~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4df002d908796c1ff87b985af1d31a0e36e6c66f;p=thirdparty%2Flinux.git

rcuscale: Allow rcuscale without RCU Tasks

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

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---

diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index dceaa3e754e5f..71e73fceff874 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -28,7 +28,6 @@ config RCU_SCALE_TEST
 	depends on DEBUG_KERNEL
 	select TORTURE_TEST
 	select SRCU
-	select TASKS_RCU
 	select TASKS_RUDE_RCU
 	select TASKS_TRACE_RCU
 	default n
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 5e4f1f83d38e7..311dbcb064edf 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -268,6 +268,8 @@ static struct rcu_scale_ops srcud_ops = {
 	.name		= "srcud"
 };
 
+#ifdef CONFIG_TASKS_RCU
+
 /*
  * Definitions for RCU-tasks scalability testing.
  */
@@ -295,6 +297,14 @@ static struct rcu_scale_ops tasks_ops = {
 	.name		= "tasks"
 };
 
+#define TASKS_OPS &tasks_ops,
+
+#else // #ifdef CONFIG_TASKS_RCU
+
+#define TASKS_OPS
+
+#endif // #else // #ifdef CONFIG_TASKS_RCU
+
 /*
  * Definitions for RCU-tasks-trace scalability testing.
  */
@@ -797,7 +807,7 @@ rcu_scale_init(void)
 	long i;
 	int firsterr = 0;
 	static struct rcu_scale_ops *scale_ops[] = {
-		&rcu_ops, &srcu_ops, &srcud_ops, &tasks_ops, &tasks_tracing_ops
+		&rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS &tasks_tracing_ops
 	};
 
 	if (!torture_init_begin(scale_type, verbose))
diff --git a/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon b/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
index 90942bb5bebc5..2ed3b46a9c378 100644
--- a/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
@@ -1,5 +1,5 @@
 CONFIG_RCU_SCALE_TEST=y
 CONFIG_PRINTK_TIME=y
 CONFIG_TASKS_RCU_GENERIC=y
-CONFIG_TASKS_RCU=y
-CONFIG_TASKS_TRACE_RCU=y
+CONFIG_FORCE_TASKS_RCU=y
+#CHECK#CONFIG_TASKS_RCU=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcuscale/TREE b/tools/testing/selftests/rcutorture/configs/rcuscale/TREE
index f110d9ffbe4cb..b10706fd03a45 100644
--- a/tools/testing/selftests/rcutorture/configs/rcuscale/TREE
+++ b/tools/testing/selftests/rcutorture/configs/rcuscale/TREE
@@ -16,3 +16,5 @@ CONFIG_RCU_BOOST=n
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
 CONFIG_RCU_EXPERT=y
 CONFIG_RCU_TRACE=y
+CONFIG_KPROBES=n
+CONFIG_FTRACE=n