diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index 4f665ae0cf55..2befd328e6a0 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -95,15 +95,23 @@ config TASKS_RUDE_RCU
switches on all online CPUs, including idle ones, so use
with caution.
-config TASKS_TRACE_RCU
- def_bool 0
- select IRQ_WORK
+config FORCE_TASKS_TRACE_RCU
+ bool "Force selection of Tasks Trace RCU"
+ depends on RCU_EXPERT
+ select TASKS_TRACE_RCU
+ default n
help
This option enables a task-based RCU implementation that uses
explicit rcu_read_lock_trace() read-side markers, and allows
- these readers to appear in the idle loop as well as on the CPU
- hotplug code paths. It can force IPIs on online CPUs, including
- idle ones, so use with caution.
+ these readers to appear in the idle loop as well as on the
+ CPU hotplug code paths. It can force IPIs on online CPUs,
+ including idle ones, so use with caution. Not for manual
+ selection in most cases.
+
+config TASKS_TRACE_RCU
+ bool
+ default n
+ select IRQ_WORK
config RCU_STALL_COMMON
def_bool TREE_RCU
@@ -227,7 +235,7 @@ config RCU_NOCB_CPU
config TASKS_TRACE_RCU_READ_MB
bool "Tasks Trace RCU readers use memory barriers in user and idle"
- depends on RCU_EXPERT
+ depends on RCU_EXPERT && TASKS_TRACE_RCU
default PREEMPT_RT || NR_CPUS < 8
help
Use this option to further reduce the number of IPIs sent
diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 4fd64999300f..d7f4bb1c4979 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -49,7 +49,6 @@ config RCU_TORTURE_TEST
select SRCU
select TASKS_RCU
select TASKS_RUDE_RCU
- select TASKS_TRACE_RCU
default n
help
This option provides a kernel module that runs torture tests
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 55d049c39608..7dd3e14ec907 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -737,6 +737,48 @@ static struct rcu_torture_ops busted_srcud_ops = {
.name = "busted_srcud"
};
+/*
+ * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
+ * This implementation does not necessarily work well with CPU hotplug.
+ */
+
+static void synchronize_rcu_trivial(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu));
+ WARN_ON_ONCE(raw_smp_processor_id() != cpu);
+ }
+}
+
+static int rcu_torture_read_lock_trivial(void) __acquires(RCU)
+{
+ preempt_disable();
+ return 0;
+}
+
+static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU)
+{
+ preempt_enable();
+}
+
+static struct rcu_torture_ops trivial_ops = {
+ .ttype = RCU_TRIVIAL_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = rcu_torture_read_lock_trivial,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_torture_read_unlock_trivial,
+ .readlock_held = torture_readlock_not_held,
+ .get_gp_seq = rcu_no_completed,
+ .sync = synchronize_rcu_trivial,
+ .exp_sync = synchronize_rcu_trivial,
+ .fqs = NULL,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "trivial"
+};
+
/*
* Definitions for RCU-tasks torture testing.
*/
@@ -780,48 +822,6 @@ static struct rcu_torture_ops tasks_ops = {
.name = "tasks"
};
-/*
- * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
- * This implementation does not necessarily work well with CPU hotplug.
- */
-
-static void synchronize_rcu_trivial(void)
-{
- int cpu;
-
- for_each_online_cpu(cpu) {
- rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu));
- WARN_ON_ONCE(raw_smp_processor_id() != cpu);
- }
-}
-
-static int rcu_torture_read_lock_trivial(void) __acquires(RCU)
-{
- preempt_disable();
- return 0;
-}
-
-static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU)
-{
- preempt_enable();
-}
-
-static struct rcu_torture_ops trivial_ops = {
- .ttype = RCU_TRIVIAL_FLAVOR,
- .init = rcu_sync_torture_init,
- .readlock = rcu_torture_read_lock_trivial,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_torture_read_unlock_trivial,
- .readlock_held = torture_readlock_not_held,
- .get_gp_seq = rcu_no_completed,
- .sync = synchronize_rcu_trivial,
- .exp_sync = synchronize_rcu_trivial,
- .fqs = NULL,
- .stats = NULL,
- .irq_capable = 1,
- .name = "trivial"
-};
-
/*
* Definitions for rude RCU-tasks torture testing.
*/
@@ -851,6 +851,8 @@ static struct rcu_torture_ops tasks_rude_ops = {
.name = "tasks-rude"
};
+#ifdef CONFIG_TASKS_TRACE_RCU
+
/*
* Definitions for tracing RCU-tasks torture testing.
*/
@@ -893,6 +895,15 @@ static struct rcu_torture_ops tasks_tracing_ops = {
.name = "tasks-tracing"
};
+#define TASKS_TRACING_OPS &tasks_tracing_ops,
+
+#else // #ifdef CONFIG_TASKS_TRACE_RCU
+
+#define TASKS_TRACING_OPS
+
+#endif // #else #ifdef CONFIG_TASKS_TRACE_RCU
+
+
static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
{
if (!cur_ops->gp_diff)
@@ -3096,9 +3107,9 @@ rcu_torture_init(void)
int flags = 0;
unsigned long gp_seq = 0;
static struct rcu_torture_ops *torture_ops[] = {
- &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
- &busted_srcud_ops, &tasks_ops, &tasks_rude_ops,
- &tasks_tracing_ops, &trivial_ops,
+ &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops,
+ &tasks_ops, &tasks_rude_ops, TASKS_TRACING_OPS
+ &trivial_ops,
};
if (!torture_init_begin(torture_type, verbose))
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
index e4d74e5fc1d0..0f5605ed1e48 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
@@ -7,5 +7,7 @@ CONFIG_PREEMPT=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_PROVE_LOCKING=n
#CHECK#CONFIG_PROVE_RCU=n
+CONFIG_FORCE_TASKS_TRACE_RCU=y
+#CHECK#CONFIG_TASKS_TRACE_RCU=y
CONFIG_TASKS_TRACE_RCU_READ_MB=y
CONFIG_RCU_EXPERT=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRACE02 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02
index 77541eeb4e9f..093ea6e8e65c 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TRACE02
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRACE02
@@ -7,5 +7,7 @@ CONFIG_PREEMPT=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
#CHECK#CONFIG_PROVE_RCU=y
+CONFIG_FORCE_TASKS_TRACE_RCU=y
+#CHECK#CONFIG_TASKS_TRACE_RCU=y
CONFIG_TASKS_TRACE_RCU_READ_MB=n
CONFIG_RCU_EXPERT=y