rcutorture: Make rcutorture support print rcu-tasks gp state

This commit make rcu-tasks related rcutorture test support rcu-tasks
gp state printing when the writer stall occurs or the at the end of
rcutorture test, and generate rcu_ops->get_gp_data() operation to
simplify the acquisition of gp state for different types of rcutorture
tests.

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

kernel/rcu/rcu.h

@@ -522,12 +522,18 @@ static inline void show_rcu_tasks_gp_kthreads(void) {}
 
 #ifdef CONFIG_TASKS_RCU
 struct task_struct *get_rcu_tasks_gp_kthread(void);
+void rcu_tasks_get_gp_data(int *flags, unsigned long *gp_seq);
 #endif // # ifdef CONFIG_TASKS_RCU
 
 #ifdef CONFIG_TASKS_RUDE_RCU
 struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
+void rcu_tasks_rude_get_gp_data(int *flags, unsigned long *gp_seq);
 #endif // # ifdef CONFIG_TASKS_RUDE_RCU
 
+#ifdef CONFIG_TASKS_TRACE_RCU
+void rcu_tasks_trace_get_gp_data(int *flags, unsigned long *gp_seq);
+#endif
+
 #ifdef CONFIG_TASKS_RCU_GENERIC
 void tasks_cblist_init_generic(void);
 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
@@ -557,8 +563,7 @@ static inline void rcu_set_jiffies_lazy_flush(unsigned long j) { }
 #endif
 
 #if defined(CONFIG_TREE_RCU)
-void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
+void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq);
-			    unsigned long *gp_seq);
 void do_trace_rcu_torture_read(const char *rcutorturename,
 			       struct rcu_head *rhp,
 			       unsigned long secs,
@@ -566,8 +571,7 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 			       unsigned long c);
 void rcu_gp_set_torture_wait(int duration);
 #else
-static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
+static inline void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq)
-					  int *flags, unsigned long *gp_seq)
 {
 	*flags = 0;
 	*gp_seq = 0;
@@ -587,20 +591,16 @@ static inline void rcu_gp_set_torture_wait(int duration) { }
 
 #ifdef CONFIG_TINY_SRCU
 
-static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
+static inline void srcutorture_get_gp_data(struct srcu_struct *sp, int *flags,
-					   struct srcu_struct *sp, int *flags,
 					   unsigned long *gp_seq)
 {
-	if (test_type != SRCU_FLAVOR)
-		return;
 	*flags = 0;
 	*gp_seq = sp->srcu_idx;
 }
 
 #elif defined(CONFIG_TREE_SRCU)
 
-void srcutorture_get_gp_data(enum rcutorture_type test_type,
+void srcutorture_get_gp_data(struct srcu_struct *sp, int *flags,
-			     struct srcu_struct *sp, int *flags,
 			     unsigned long *gp_seq);
 
 #endif

kernel/rcu/rcutorture.c

@@ -381,6 +381,7 @@ struct rcu_torture_ops {
 	void (*gp_kthread_dbg)(void);
 	bool (*check_boost_failed)(unsigned long gp_state, int *cpup);
 	int (*stall_dur)(void);
+	void (*get_gp_data)(int *flags, unsigned long *gp_seq);
 	long cbflood_max;
 	int irq_capable;
 	int can_boost;
@@ -569,6 +570,7 @@ static struct rcu_torture_ops rcu_ops = {
 	.gp_kthread_dbg		= show_rcu_gp_kthreads,
 	.check_boost_failed	= rcu_check_boost_fail,
 	.stall_dur		= rcu_jiffies_till_stall_check,
+	.get_gp_data		= rcutorture_get_gp_data,
 	.irq_capable		= 1,
 	.can_boost		= IS_ENABLED(CONFIG_RCU_BOOST),
 	.extendables		= RCUTORTURE_MAX_EXTEND,
@@ -628,6 +630,11 @@ static struct srcu_struct srcu_ctld;
 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
 static struct rcu_torture_ops srcud_ops;
 
+static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
+{
+	srcutorture_get_gp_data(srcu_ctlp, flags, gp_seq);
+}
+
 static int srcu_torture_read_lock(void)
 {
 	if (cur_ops == &srcud_ops)
@@ -736,6 +743,7 @@ static struct rcu_torture_ops srcu_ops = {
 	.call		= srcu_torture_call,
 	.cb_barrier	= srcu_torture_barrier,
 	.stats		= srcu_torture_stats,
+	.get_gp_data	= srcu_get_gp_data,
 	.cbflood_max	= 50000,
 	.irq_capable	= 1,
 	.no_pi_lock	= IS_ENABLED(CONFIG_TINY_SRCU),
@@ -774,6 +782,7 @@ static struct rcu_torture_ops srcud_ops = {
 	.call		= srcu_torture_call,
 	.cb_barrier	= srcu_torture_barrier,
 	.stats		= srcu_torture_stats,
+	.get_gp_data	= srcu_get_gp_data,
 	.cbflood_max	= 50000,
 	.irq_capable	= 1,
 	.no_pi_lock	= IS_ENABLED(CONFIG_TINY_SRCU),
@@ -882,6 +891,7 @@ static struct rcu_torture_ops tasks_ops = {
 	.call		= call_rcu_tasks,
 	.cb_barrier	= rcu_barrier_tasks,
 	.gp_kthread_dbg	= show_rcu_tasks_classic_gp_kthread,
+	.get_gp_data	= rcu_tasks_get_gp_data,
 	.fqs		= NULL,
 	.stats		= NULL,
 	.irq_capable	= 1,
@@ -922,6 +932,7 @@ static struct rcu_torture_ops tasks_rude_ops = {
 	.call		= call_rcu_tasks_rude,
 	.cb_barrier	= rcu_barrier_tasks_rude,
 	.gp_kthread_dbg	= show_rcu_tasks_rude_gp_kthread,
+	.get_gp_data	= rcu_tasks_rude_get_gp_data,
 	.cbflood_max	= 50000,
 	.fqs		= NULL,
 	.stats		= NULL,
@@ -974,6 +985,7 @@ static struct rcu_torture_ops tasks_tracing_ops = {
 	.call		= call_rcu_tasks_trace,
 	.cb_barrier	= rcu_barrier_tasks_trace,
 	.gp_kthread_dbg	= show_rcu_tasks_trace_gp_kthread,
+	.get_gp_data    = rcu_tasks_trace_get_gp_data,
 	.cbflood_max	= 50000,
 	.fqs		= NULL,
 	.stats		= NULL,
@@ -2264,10 +2276,8 @@ rcu_torture_stats_print(void)
 		int __maybe_unused flags = 0;
 		unsigned long __maybe_unused gp_seq = 0;
 
-		rcutorture_get_gp_data(cur_ops->ttype,
+		if (cur_ops->get_gp_data)
-				       &flags, &gp_seq);
+			cur_ops->get_gp_data(&flags, &gp_seq);
-		srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
-					&flags, &gp_seq);
 		wtp = READ_ONCE(writer_task);
 		pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n",
 			 rcu_torture_writer_state_getname(),
@@ -3390,8 +3400,8 @@ rcu_torture_cleanup(void)
 		fakewriter_tasks = NULL;
 	}
 
-	rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
+	if (cur_ops->get_gp_data)
-	srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
+		cur_ops->get_gp_data(&flags, &gp_seq);
 	pr_alert("%s:  End-test grace-period state: g%ld f%#x total-gps=%ld\n",
 		 cur_ops->name, (long)gp_seq, flags,
 		 rcutorture_seq_diff(gp_seq, start_gp_seq));
@@ -3762,8 +3772,8 @@ rcu_torture_init(void)
 			nrealreaders = 1;
 	}
 	rcu_torture_print_module_parms(cur_ops, "Start of test");
-	rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
+	if (cur_ops->get_gp_data)
-	srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
+		cur_ops->get_gp_data(&flags, &gp_seq);
 	start_gp_seq = gp_seq;
 	pr_alert("%s:  Start-test grace-period state: g%ld f%#x\n",
 		 cur_ops->name, (long)gp_seq, flags);

kernel/rcu/srcutree.c

@@ -1826,12 +1826,9 @@ static void process_srcu(struct work_struct *work)
 	srcu_reschedule(ssp, curdelay);
 }
 
-void srcutorture_get_gp_data(enum rcutorture_type test_type,
+void srcutorture_get_gp_data(struct srcu_struct *ssp, int *flags,
-			     struct srcu_struct *ssp, int *flags,
 			     unsigned long *gp_seq)
 {
-	if (test_type != SRCU_FLAVOR)
-		return;
 	*flags = 0;
 	*gp_seq = rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq);
 }

kernel/rcu/tasks.h

@@ -1178,6 +1178,13 @@ struct task_struct *get_rcu_tasks_gp_kthread(void)
 }
 EXPORT_SYMBOL_GPL(get_rcu_tasks_gp_kthread);
 
+void rcu_tasks_get_gp_data(int *flags, unsigned long *gp_seq)
+{
+	*flags = 0;
+	*gp_seq = rcu_seq_current(&rcu_tasks.tasks_gp_seq);
+}
+EXPORT_SYMBOL_GPL(rcu_tasks_get_gp_data);
+
 /*
  * Protect against tasklist scan blind spot while the task is exiting and
  * may be removed from the tasklist.  Do this by adding the task to yet
@@ -1358,6 +1365,13 @@ struct task_struct *get_rcu_tasks_rude_gp_kthread(void)
 }
 EXPORT_SYMBOL_GPL(get_rcu_tasks_rude_gp_kthread);
 
+void rcu_tasks_rude_get_gp_data(int *flags, unsigned long *gp_seq)
+{
+	*flags = 0;
+	*gp_seq = rcu_seq_current(&rcu_tasks_rude.tasks_gp_seq);
+}
+EXPORT_SYMBOL_GPL(rcu_tasks_rude_get_gp_data);
+
 #endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
 
 ////////////////////////////////////////////////////////////////////////
@@ -2010,6 +2024,13 @@ struct task_struct *get_rcu_tasks_trace_gp_kthread(void)
 }
 EXPORT_SYMBOL_GPL(get_rcu_tasks_trace_gp_kthread);
 
+void rcu_tasks_trace_get_gp_data(int *flags, unsigned long *gp_seq)
+{
+	*flags = 0;
+	*gp_seq = rcu_seq_current(&rcu_tasks_trace.tasks_gp_seq);
+}
+EXPORT_SYMBOL_GPL(rcu_tasks_trace_get_gp_data);
+
 #else /* #ifdef CONFIG_TASKS_TRACE_RCU */
 static void exit_tasks_rcu_finish_trace(struct task_struct *t) { }
 #endif /* #else #ifdef CONFIG_TASKS_TRACE_RCU */

kernel/rcu/tree.c

@@ -508,17 +508,10 @@ static struct rcu_node *rcu_get_root(void)
 /*
  * Send along grace-period-related data for rcutorture diagnostics.
  */
-void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
+void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq)
-			    unsigned long *gp_seq)
 {
-	switch (test_type) {
+	*flags = READ_ONCE(rcu_state.gp_flags);
-	case RCU_FLAVOR:
+	*gp_seq = rcu_seq_current(&rcu_state.gp_seq);
-		*flags = READ_ONCE(rcu_state.gp_flags);
-		*gp_seq = rcu_seq_current(&rcu_state.gp_seq);
-		break;
-	default:
-		break;
-	}
 }
 EXPORT_SYMBOL_GPL(rcutorture_get_gp_data);