On Fri, Sep 11, 2026 at 05:35:15PM +0800, Kunwu Chan wrote:
> Add the lockdep annotation, same-type SRCU nesting warning, and
> early-boot check used by __synchronize_srcu().
>
> Suggested-by: Zqiang <[email protected]>
> Signed-off-by: Kunwu Chan <[email protected]>
Queued for review and testing, thank you both!
Interestingly enough, it is now the case that there is a grace-period
wait that can be placed in a normal RCU read-side critical section.
Does this mean that we should also adjust the --do-srcu-lockdep testing
in tools/testing/selftests/rcutorture/bin/torture.sh?
Thanx, Paul
> ---
> kernel/rcu/srcutree.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> index 6a9c432a3bd0..6c729e805fb3 100644
> --- a/kernel/rcu/srcutree.c
> +++ b/kernel/rcu/srcutree.c
> @@ -2123,6 +2123,14 @@ void synchronize_srcu_atomic(struct srcu_struct *ssp)
> unsigned long rdm0, rdm1;
> unsigned long unlocks0, unlocks1;
>
> + srcu_lock_sync(&ssp->dep_map);
> +
> + RCU_LOCKDEP_WARN(lockdep_is_held(ssp),
> + "Illegal synchronize_srcu_atomic() in same-type SRCU
> read-side critical section");
> +
> + if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE)
> + return;
> +
> // Initialize. Either init_srcu_struct() was invoked or
> // DEFINE_SRCU() or similar was used. Therefore, no allocation
> // will be done here.
> --
> 2.43.0
>
