Re: [PATCH v3 1/4] rcutorture: Update due to x86 not supporting none/voluntary preemption
From: Boqun Feng
Date: Thu Mar 05 2026 - 13:22:46 EST
Hi Paul,
On Wed, Mar 04, 2026 at 04:01:19PM -0800, Paul E. McKenney wrote:
> As of v7.0-rc1, architectures that support preemption, including x86 and
> arm64, no longer support CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY.
> Attempting to build kernels with these two Kconfig options results in
> .config errors. This commit therefore switches such rcutorture scenarios
> to CONFIG_PREEMPT_LAZY.
>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
>
> ---
>
> Changes since v2:
>
> o Fold in c69ac5693540 ("rcutorture: Adjust scenarios for default
> lazy preemption")
>
I'm not sure I got what the "Fold" here means? I think you didn't do the
fold? Because..
> Changes since v1:
>
> o Add CONFIG_PREEMPT_DYNAMIC=n in order to test non-preemptible RCU.
>
> o Remove CONFIG_PREEMPT_COUNT=n because it conflicts with
> CONFIG_PREEMPT_LAZY=y.
>
> o Remove some stray conflicting CONFIG_PREEMPT_LAZY=n instances.
>
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N
> index 07f5e0a70ae70..f943cdfb0a741 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N
> @@ -2,7 +2,9 @@ CONFIG_RCU_TRACE=n
> CONFIG_SMP=y
> CONFIG_NR_CPUS=4
> CONFIG_HOTPLUG_CPU=y
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_DYNAMIC=n
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> #CHECK#CONFIG_RCU_EXPERT=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-T b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-T
> index c70cf0405f248..06e4d1030279c 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-T
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-T
> @@ -1,5 +1,6 @@
> CONFIG_SMP=n
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-U b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-U
> index bc9eeabaa1b18..71da6e3e94886 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-U
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-U
> @@ -1,5 +1,6 @@
> CONFIG_SMP=n
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> @@ -7,4 +8,3 @@ CONFIG_PREEMPT_DYNAMIC=n
> CONFIG_RCU_TRACE=n
> CONFIG_DEBUG_LOCK_ALLOC=n
> CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
> -CONFIG_PREEMPT_COUNT=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS02 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS02
> index 2f9fcffff5ae3..dd2bd4e08da4e 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS02
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS02
> @@ -1,5 +1,6 @@
> CONFIG_SMP=n
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TINY01 b/tools/testing/selftests/rcutorture/configs/rcu/TINY01
> index bd5ed7b0da5f0..2be53bf60d65b 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TINY01
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TINY01
> @@ -1,9 +1,9 @@
> CONFIG_SMP=n
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> -CONFIG_PREEMPT_LAZY=n
This is the line that was introduced by the said commit, hence this
patch is still separate from that commit I think?
Regards,
Boqun
> #CHECK#CONFIG_TINY_RCU=y
> CONFIG_HZ_PERIODIC=n
> CONFIG_NO_HZ_IDLE=y
> @@ -12,4 +12,3 @@ CONFIG_RCU_TRACE=n
> #CHECK#CONFIG_RCU_STALL_COMMON=n
> CONFIG_DEBUG_LOCK_ALLOC=n
> CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
> -CONFIG_PREEMPT_COUNT=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TINY02 b/tools/testing/selftests/rcutorture/configs/rcu/TINY02
> index 30439f6fc20e6..be8860342ef71 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TINY02
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TINY02
> @@ -1,5 +1,6 @@
> CONFIG_SMP=n
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
> index 18efab346381a..8fb124c28f283 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
> @@ -1,7 +1,8 @@
> CONFIG_SMP=y
> CONFIG_NR_CPUS=5
> CONFIG_HOTPLUG_CPU=y
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04
> index 34aee1acb8662..ac857d5bcb222 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE04
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE04
> @@ -1,11 +1,12 @@
> CONFIG_SMP=y
> CONFIG_NR_CPUS=8
> +CONFIG_PREEMPT_LAZY=y
> CONFIG_PREEMPT_NONE=n
> -CONFIG_PREEMPT_VOLUNTARY=y
> +CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> -CONFIG_PREEMPT_LAZY=n
> #CHECK#CONFIG_TREE_RCU=y
> +#CHECK#CONFIG_PREEMPT_RCU=n
> CONFIG_HZ_PERIODIC=n
> CONFIG_NO_HZ_IDLE=n
> CONFIG_NO_HZ_FULL=y
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05
> index 0513aa33c32c4..61d15b1b54d16 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE05
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE05
> @@ -1,9 +1,10 @@
> CONFIG_SMP=y
> CONFIG_NR_CPUS=8
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_DYNAMIC=n
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> -CONFIG_PREEMPT_LAZY=n
> #CHECK#CONFIG_TREE_RCU=y
> CONFIG_HZ_PERIODIC=n
> CONFIG_NO_HZ_IDLE=y
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06
> index cc3ea23c76557..0e090bb68a0f6 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE06
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE06
> @@ -1,10 +1,12 @@
> CONFIG_SMP=y
> CONFIG_NR_CPUS=8
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_DYNAMIC=n
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> -CONFIG_PREEMPT_LAZY=n
> #CHECK#CONFIG_TREE_RCU=y
> +#CHECK#CONFIG_PREEMPT_RCU=n
> CONFIG_HZ_PERIODIC=n
> CONFIG_NO_HZ_IDLE=y
> CONFIG_NO_HZ_FULL=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE10 b/tools/testing/selftests/rcutorture/configs/rcu/TREE10
> index 420632b030dc4..b2ce37861e71a 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE10
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE10
> @@ -6,6 +6,7 @@ CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_PREEMPT_DYNAMIC=n
> #CHECK#CONFIG_TREE_RCU=y
> +CONFIG_PREEMPT_RCU=n
> CONFIG_HZ_PERIODIC=n
> CONFIG_NO_HZ_IDLE=y
> CONFIG_NO_HZ_FULL=n
> diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
> index 5d546efa68e83..696fba9968c60 100644
> --- a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
> +++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
> @@ -1,6 +1,8 @@
> CONFIG_SMP=y
> CONFIG_NR_CPUS=8
> -CONFIG_PREEMPT_NONE=y
> +CONFIG_PREEMPT_DYNAMIC=n
> +CONFIG_PREEMPT_LAZY=y
> +CONFIG_PREEMPT_NONE=n
> CONFIG_PREEMPT_VOLUNTARY=n
> CONFIG_PREEMPT=n
> CONFIG_HZ_PERIODIC=n
>