Commit bfba7ed0 authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony) Committed by Paul E. McKenney
Browse files

rcu-tasks: Add RCU-tasks self tests 



This commit adds self tests for early-boot use of RCU-tasks grace periods.
It tests all three variants (Rude, Tasks, and Tasks Trace) and covers
both synchronous (e.g., synchronize_rcu_tasks()) and asynchronous (e.g.,
call_rcu_tasks()) grace-period APIs.

Self-tests are run only in kernels built with CONFIG_PROVE_RCU=y.

Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
[ paulmck: Handle CONFIG_PROVE_RCU=n and identify test cases' callbacks. ]
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 7dffe017

kernel/rcu/tasks.h

+79 −0
Original line number Diff line number Diff line
@@ -1231,6 +1231,82 @@ void show_rcu_tasks_gp_kthreads(void) 
}

#endif /* #ifndef CONFIG_TINY_RCU */



#ifdef CONFIG_PROVE_RCU

struct rcu_tasks_test_desc {

	struct rcu_head rh;

	const char *name;

	bool notrun;

};



static struct rcu_tasks_test_desc tests[] = {

	{

		.name = "call_rcu_tasks()",

		/* If not defined, the test is skipped. */

		.notrun = !IS_ENABLED(CONFIG_TASKS_RCU),

	},

	{

		.name = "call_rcu_tasks_rude()",

		/* If not defined, the test is skipped. */

		.notrun = !IS_ENABLED(CONFIG_TASKS_RUDE_RCU),

	},

	{

		.name = "call_rcu_tasks_trace()",

		/* If not defined, the test is skipped. */

		.notrun = !IS_ENABLED(CONFIG_TASKS_TRACE_RCU)

	}

};



static void test_rcu_tasks_callback(struct rcu_head *rhp)

{

	struct rcu_tasks_test_desc *rttd =

		container_of(rhp, struct rcu_tasks_test_desc, rh);



	pr_info("Callback from %s invoked.\n", rttd->name);



	rttd->notrun = true;

}



static void rcu_tasks_initiate_self_tests(void)

{

	pr_info("Running RCU-tasks wait API self tests\n");

#ifdef CONFIG_TASKS_RCU

	synchronize_rcu_tasks();

	call_rcu_tasks(&tests[0].rh, test_rcu_tasks_callback);

#endif



#ifdef CONFIG_TASKS_RUDE_RCU

	synchronize_rcu_tasks_rude();

	call_rcu_tasks_rude(&tests[1].rh, test_rcu_tasks_callback);

#endif



#ifdef CONFIG_TASKS_TRACE_RCU

	synchronize_rcu_tasks_trace();

	call_rcu_tasks_trace(&tests[2].rh, test_rcu_tasks_callback);

#endif

}



static int rcu_tasks_verify_self_tests(void)

{

	int ret = 0;

	int i;



	for (i = 0; i < ARRAY_SIZE(tests); i++) {

		if (!tests[i].notrun) {		// still hanging.

			pr_err("%s has been failed.\n", tests[i].name);

			ret = -1;

		}

	}



	if (ret)

		WARN_ON(1);



	return ret;

}

late_initcall(rcu_tasks_verify_self_tests);

#else /* #ifdef CONFIG_PROVE_RCU */

static void rcu_tasks_initiate_self_tests(void) { }

#endif /* #else #ifdef CONFIG_PROVE_RCU */



void __init rcu_init_tasks_generic(void)

{

#ifdef CONFIG_TASKS_RCU
@@ -1244,6 +1320,9 @@ void __init rcu_init_tasks_generic(void) 
#ifdef CONFIG_TASKS_TRACE_RCU

	rcu_spawn_tasks_trace_kthread();

#endif



	// Run the self-tests.

	rcu_tasks_initiate_self_tests();

}



#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */