Merge branch 'for-mingo-rcu' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul E. McKenney:

- Documentation updates.

- Miscellaneous fixes.

- kfree_rcu() updates: Addition of mem_dump_obj() to provide allocator return
  addresses to more easily locate bugs.  This has a couple of RCU-related commits,
  but is mostly MM.  Was pulled in with akpm's agreement.

- Per-callback-batch tracking of numbers of callbacks,
  which enables better debugging information and smarter
  reactions to large numbers of callbacks.

- The first round of changes to allow CPUs to be runtime switched from and to
  callback-offloaded state.

- CONFIG_PREEMPT_RT-related changes.

- RCU CPU stall warning updates.
- Addition of polling grace-period APIs for SRCU.

- Torture-test and torture-test scripting updates, including a "torture everything"
  script that runs rcutorture, locktorture, scftorture, rcuscale, and refscale.
  Plus does an allmodconfig build.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 36607551f966..af7c19439f4e 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1224,6 +1224,82 @@ 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
@@ -1237,6 +1313,9 @@ 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 */