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

[Paul E. McKenney]

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@xxxxxxxxxx>

For 3/4 and 4/4:

Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Tested-by: Paul E. McKenney <paulmck@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
>