[PATCH RFC v1 4/4] rcutorture: Add NOCB02 config for nocb poll mode testing

From: Joel Fernandes

Date: Tue Feb 24 2026 - 18:10:15 EST


Add new rcutorture config NOCB02 that enables rcu_nocb_poll boot
parameter combined with CONFIG_RCU_NOCB_CPU to exercise the polling
mode code paths in the NOCB implementation.

This config exercises poll-mode paths not covered by other configs,
where callback invocation uses active polling instead of kthread
wakeups.

This config is not added to CFLIST to avoid increasing the default
test duration; it can be run explicitly when poll-mode testing
is needed.

Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
---
.../selftests/rcutorture/configs/rcu/NOCB02 | 20 +++++++++++++++++++
.../rcutorture/configs/rcu/NOCB02.boot | 3 +++
2 files changed, 23 insertions(+)
create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/NOCB02
create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/NOCB02.boot

diff --git a/tools/testing/selftests/rcutorture/configs/rcu/NOCB02 b/tools/testing/selftests/rcutorture/configs/rcu/NOCB02
new file mode 100644
index 000000000000..4c2b8cd6d8fd
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/NOCB02
@@ -0,0 +1,20 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=8
+CONFIG_PREEMPT_NONE=n
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=y
+#CHECK#CONFIG_PREEMPT_RCU=y
+CONFIG_HZ_PERIODIC=n
+CONFIG_NO_HZ_IDLE=y
+CONFIG_NO_HZ_FULL=n
+CONFIG_RCU_TRACE=y
+CONFIG_HOTPLUG_CPU=y
+CONFIG_RCU_FANOUT=3
+CONFIG_RCU_FANOUT_LEAF=2
+CONFIG_RCU_NOCB_CPU=y
+CONFIG_DEBUG_LOCK_ALLOC=n
+CONFIG_PROVE_LOCKING=n
+CONFIG_RCU_BOOST=n
+CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
+CONFIG_RCU_EXPERT=y
+CONFIG_RCU_EQS_DEBUG=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/NOCB02.boot b/tools/testing/selftests/rcutorture/configs/rcu/NOCB02.boot
new file mode 100644
index 000000000000..c212ae299b0b
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/NOCB02.boot
@@ -0,0 +1,3 @@
+rcupdate.rcu_self_test=1
+rcu_nocbs=all
+rcu_nocb_poll
--
2.34.1