On Thu, Mar 05, 2026 at 12:53:48PM -0500, Joel Fernandes wrote: > > > On 3/4/2026 7:01 PM, 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 <[email protected]> > > > > --- > > > > Changes since v2: > > > > o Fold in c69ac5693540 ("rcutorture: Adjust scenarios for default > > lazy preemption") > > > > 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/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 > > nit: Let us add this #CHECK# to the other configs you changed too? Otherwise > it > is a bit confusing because it took some digging to clearly see that > PREEMPT_DYNAMIC=n and PREEMPT_LAZY=y implies CONFIG_PREEMPT_RCU=n ;-)
Tell me about it. ;-) I will add "#CHECK#CONFIG_PREEMPT_RCU=n" as a separate non-urgent commit. > Otherwise, I could not find any other flaws in the approach and it makes > sense, so: > Reviewed-by: Joel Fernandes <[email protected]> > > Boqun, you will be taking this through the 7.0-rc tree right? So that 7.0 > release tests don't fail. Unless I hear otherwise, I will assume that Boqun will apply your Reviewed-by. Easy for me to do, just no point in its being done twice. > Also I will drop the 2 related rcutorture patches for 7.1 and rebase on top > of a > 7.0-rc fixes branch Boqun might be creating. Sounds good, and thank you both! Thanx, Paul > Thanks! > > -- > Joel Fernandes > > [...] >
