On Fri, Feb 14, 2020 at 04:25:19PM -0800, paulmck@xxxxxxxxxx wrote:
> From: Jules Irenge <jbi.octave@xxxxxxxxx>
>
> Sparse reports a warning at exit_tasks_rcu_start(void)
>
> |warning: context imbalance in exit_tasks_rcu_start() - wrong count at exit
>
> To fix this, this commit adds an __acquires(&tasks_rcu_exit_srcu).
> Given that exit_tasks_rcu_start() does actually call __srcu_read_lock(),
> this not only fixes the warning but also improves on the readability of
> the code.
For patch 1/3 and 2/3:
Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Though IMO it would be good to squash both the patches.
thanks,
- Joel
> Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> ---
> kernel/rcu/update.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
> index a27df76..a04fe54 100644
> --- a/kernel/rcu/update.c
> +++ b/kernel/rcu/update.c
> @@ -801,7 +801,7 @@ static int __init rcu_spawn_tasks_kthread(void)
> core_initcall(rcu_spawn_tasks_kthread);
>
> /* Do the srcu_read_lock() for the above synchronize_srcu(). */
> -void exit_tasks_rcu_start(void)
> +void exit_tasks_rcu_start(void) __acquires(&tasks_rcu_exit_srcu)
> {
> preempt_disable();
> current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu);
> --
> 2.9.5
>
