From a15ec57cfcf83858aced058e00a7feb824322fa4 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@kernel.org>
Date: Sat, 3 Jun 2023 09:07:44 -0700
Subject: [PATCH] rcuscale: Add RCU Tasks Rude testing

Add a "tasks-rude" option to the rcuscale.scale_type module parameter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcu.h                              |  3 ++
 kernel/rcu/rcuscale.c                         | 31 ++++++++++++++++++-
 kernel/rcu/tasks.h                            |  7 +++++
 .../rcutorture/configs/rcuscale/CFcommon      |  2 ++
 4 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index d58bc0e86769..9829d8161b21 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -508,6 +508,9 @@ void show_rcu_tasks_gp_kthreads(void);
 # ifdef CONFIG_TASKS_RCU
 struct task_struct *get_rcu_tasks_gp_kthread(void);
 # endif // # ifdef CONFIG_TASKS_RCU
+# ifdef CONFIG_TASKS_RUDE_RCU
+struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
+# endif // # ifdef CONFIG_TASKS_RUDE_RCU
 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
 static inline void show_rcu_tasks_gp_kthreads(void) {}
 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 35e06c86acc9..5ce3b4e7ce71 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -310,6 +310,35 @@ static struct rcu_scale_ops tasks_ops = {
 
 #endif // #else // #ifdef CONFIG_TASKS_RCU
 
+#ifdef CONFIG_TASKS_RUDE_RCU
+
+/*
+ * Definitions for RCU-tasks-rude scalability testing.
+ */
+
+static struct rcu_scale_ops tasks_rude_ops = {
+	.ptype		= RCU_TASKS_RUDE_FLAVOR,
+	.init		= rcu_sync_scale_init,
+	.readlock	= tasks_scale_read_lock,
+	.readunlock	= tasks_scale_read_unlock,
+	.get_gp_seq	= rcu_no_completed,
+	.gp_diff	= rcu_seq_diff,
+	.async		= call_rcu_tasks_rude,
+	.gp_barrier	= rcu_barrier_tasks_rude,
+	.sync		= synchronize_rcu_tasks_rude,
+	.exp_sync	= synchronize_rcu_tasks_rude,
+	.rso_gp_kthread	= get_rcu_tasks_rude_gp_kthread,
+	.name		= "tasks-rude"
+};
+
+#define TASKS_RUDE_OPS &tasks_rude_ops,
+
+#else // #ifdef CONFIG_TASKS_RUDE_RCU
+
+#define TASKS_RUDE_OPS
+
+#endif // #else // #ifdef CONFIG_TASKS_RUDE_RCU
+
 #ifdef CONFIG_TASKS_TRACE_RCU
 
 /*
@@ -913,7 +942,7 @@ rcu_scale_init(void)
 	long i;
 	int firsterr = 0;
 	static struct rcu_scale_ops *scale_ops[] = {
-		&rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_TRACING_OPS
+		&rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS
 	};
 
 	if (!torture_init_begin(scale_type, verbose))
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 0f03de023097..0372c5cbc83b 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1194,6 +1194,13 @@ void show_rcu_tasks_rude_gp_kthread(void)
 }
 EXPORT_SYMBOL_GPL(show_rcu_tasks_rude_gp_kthread);
 #endif // !defined(CONFIG_TINY_RCU)
+
+struct task_struct *get_rcu_tasks_rude_gp_kthread(void)
+{
+	return rcu_tasks_rude.kthread_ptr;
+}
+EXPORT_SYMBOL_GPL(get_rcu_tasks_rude_gp_kthread);
+
 #endif /* #ifdef CONFIG_TASKS_RUDE_RCU */
 
 ////////////////////////////////////////////////////////////////////////
diff --git a/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon b/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
index 6a00157bee5b..b1ffd7c67604 100644
--- a/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcuscale/CFcommon
@@ -2,5 +2,7 @@ CONFIG_RCU_SCALE_TEST=y
 CONFIG_PRINTK_TIME=y
 CONFIG_FORCE_TASKS_RCU=y
 #CHECK#CONFIG_TASKS_RCU=y
+CONFIG_FORCE_TASKS_RUDE_RCU=y
+#CHECK#CONFIG_TASKS_RUDE_RCU=y
 CONFIG_FORCE_TASKS_TRACE_RCU=y
 #CHECK#CONFIG_TASKS_TRACE_RCU=y