From: Boqun Feng <boqun@kernel.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, rostedt@goodmis.org
Subject: Re: [PATCH v3 1/4] rcutorture: Update due to x86 not supporting none/voluntary preemption
Date: Thu, 5 Mar 2026 11:59:35 -0800 [thread overview]
Message-ID: <aangp2xaOayAC8dy@tardis.local> (raw)
In-Reply-To: <58f83c55-51cf-4a77-a5d1-3a5adfe9e4c2@paulmck-laptop>
On Thu, Mar 05, 2026 at 11:06:25AM -0800, Paul E. McKenney wrote:
> On Thu, Mar 05, 2026 at 10:22:35AM -0800, Boqun Feng wrote:
[...]
> > > 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?
>
> I *think* I have them folded/squashed correctly.
>
> I pushed this out to my -rcu "dev" branch. The relevant commits are,
> in order of increasing time of commit:
>
> c70ac5693540 ("rcutorture: Adjust scenarios for default lazy preemption")
It's the commit c69ac5693540 in your "dev" branch, right?
> 86126bc6d7ad ("rcutorture: Update due to x86 not supporting none/voluntary preemption")
> 5631c1565493 ("Revert "rcutorture: Adjust scenarios for default lazy preemption"")
> 6fd95cee7427 ("Revert "rcutorture: Update due to x86 not supporting none/voluntary preemption"")
The thing is the combination of the above 4 didn't introduce a clean
base in rcu/{TINY01, TREE04, TREE05, TREE06}, as shown by:
git diff 'c69ac5693540^..6fd95cee7427' -- tools/testing/selftests/rcutorture/configs/rcu/{TINY01,TREE04,TREE05,TREE06}
I took a look, it's because commit 86126bc6d7ad ("rcutorture: Update due
to x86 not supporting none/voluntary preemption") was based on commit
c69ac5693540, and it moved a few CONFIG_PREEMPT_LAZY configs, and when
it got reverted in commit 6fd95cee7427, these configs were moved back so
commit 5631c1565493's revert was partially reverted.
> 17c52d7b31a1 ("rcutorture: Update due to x86 not supporting none/voluntary preemption")
>
A simple way to verify would be try `cherry-pick` this commit onto
7.0-rc1.
Regards,
Boqun
> The first was applied by Joel to the shared RCU tree, the second is in my
> -rcu tree, and the last three are consecutive commits in my -rcu tree.
> The following command gives no output, which I was interpreting as my
> having done it correctly. But please double-check.
>
> git diff 5631c1565493^..17c52d7b31a1
>
> Thanx, Paul
>
> > 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
> > >
>
next prev parent reply other threads:[~2026-03-05 19:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-03 23:58 [PATCH 0/4] rcu: Fix lazy-preemption regression in torture-test suites Paul E. McKenney
2026-03-03 23:59 ` [PATCH 1/4] rcutorture: Update due to x86 not supporting none/voluntary preemption Paul E. McKenney
2026-03-04 17:26 ` [PATCH v2 " Paul E. McKenney
2026-03-05 0:01 ` [PATCH v3 " Paul E. McKenney
2026-03-05 17:53 ` Joel Fernandes
2026-03-05 19:08 ` Paul E. McKenney
2026-03-05 18:22 ` Boqun Feng
2026-03-05 19:06 ` Paul E. McKenney
2026-03-05 19:59 ` Boqun Feng [this message]
2026-03-05 20:11 ` Paul E. McKenney
2026-03-05 21:08 ` Boqun Feng
2026-03-05 23:24 ` Paul E. McKenney
2026-03-03 23:59 ` [PATCH 2/4] rcuscale: " Paul E. McKenney
2026-03-03 23:59 ` [PATCH 3/4] refscale: " Paul E. McKenney
2026-03-03 23:59 ` [PATCH 4/4] scftorture: " Paul E. McKenney
2026-03-05 21:29 ` [PATCH 0/4] rcu: Fix lazy-preemption regression in torture-test suites Boqun Feng
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