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

[Joel Fernandes <joelagnelf@nvidia.com>]

> On Feb 25, 2026, at 4:47 PM, Paul E. McKenney <paulmck@kernel.org> wrote:
> 
> On Tue, Feb 24, 2026 at 06:04:35PM -0500, Joel Fernandes wrote:
>> 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@nvidia.com>
> 
> For 3/4 and 4/4:
> 
> Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
> Tested-by: Paul E. McKenney <paulmck@kernel.org>

Thanks, will apply these 2 to 7.1 with the tag.

Joel




> 
>> ---
>> .../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
>>