Re: [PATCH 2/2] rcu-tasks: add RCU-tasks self tests

[Uladzislau Rezki]

> Add self tests for checking of RCU-tasks API functionality.
> It covers:
>     - wait API functions;
>     - invoking/completion call_rcu_tasks*().
> 
> Self-tests are run when CONFIG_PROVE_RCU kernel parameter is set.
> 
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
> ---
>  kernel/rcu/tasks.h | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> index 67a162949763..9407772780c1 100644
> --- a/kernel/rcu/tasks.h
> +++ b/kernel/rcu/tasks.h
> @@ -1225,6 +1225,16 @@ void show_rcu_tasks_gp_kthreads(void)
>  }
>  #endif /* #ifndef CONFIG_TINY_RCU */
>  
> +static struct rcu_head rhp;
> +static int rcu_execurted_test_counter;
> +static int rcu_run_test_counter;
> +
> +static void test_rcu_tasks_callback(struct rcu_head *r)
> +{
> +	pr_info("RCU-tasks test callback executed %d\n",
> +		++rcu_execurted_test_counter);
> +}
> +
>  void __init rcu_init_tasks_generic(void)
>  {
>  #ifdef CONFIG_TASKS_RCU
> @@ -1238,7 +1248,41 @@ void __init rcu_init_tasks_generic(void)
>  #ifdef CONFIG_TASKS_TRACE_RCU
>  	rcu_spawn_tasks_trace_kthread();
>  #endif
> +
> +	if (IS_ENABLED(CONFIG_PROVE_RCU)) {
> +		pr_info("Running RCU-tasks wait API self tests\n");
> +#ifdef CONFIG_TASKS_RCU
> +		rcu_run_test_counter++;
> +		call_rcu_tasks(&rhp, test_rcu_tasks_callback);
> +		synchronize_rcu_tasks();
> +#endif
> +
> +#ifdef CONFIG_TASKS_RUDE_RCU
> +		rcu_run_test_counter++;
> +		call_rcu_tasks_trace(&rhp, test_rcu_tasks_callback);
> +		synchronize_rcu_tasks_rude();
> +#endif
> +
> +#ifdef CONFIG_TASKS_TRACE_RCU
> +		rcu_run_test_counter++;
> +		call_rcu_tasks_trace(&rhp, test_rcu_tasks_callback);
> +		synchronize_rcu_tasks_trace();
> +#endif
> +	}
> +}
> +
> +static int rcu_tasks_verify_self_tests(void)
> +{
> +	int ret = 0;
> +
> +	if (rcu_run_test_counter != rcu_execurted_test_counter) {
> +		WARN_ON(1);
> +		ret = -1;
> +	}
> +
> +	return ret;
>  }
> +late_initcall(rcu_tasks_verify_self_tests);
>  
>  #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
>  static inline void rcu_tasks_bootup_oddness(void) {}
Please find a v2 of the patch that is in question. First version
uses the same rhp for all RCU flavors what is wrong. Initially
i had three different one per one flavor. But for some reason
end up with only one.