[PATCH rcu 6/9] rcu: Add test code for semaphore-like SRCU readers

From: Paul E. McKenney
Date: Wed Jan 04 2023 - 19:37:24 EST


This commit adds trivial test code for srcu_down_read() and
srcu_up_read().

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/update.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index a5b4abbee6439..a72f98c120f09 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -555,9 +555,12 @@ struct early_boot_kfree_rcu {
static void early_boot_test_call_rcu(void)
{
static struct rcu_head head;
+ int idx;
static struct rcu_head shead;
struct early_boot_kfree_rcu *rhp;

+ idx = srcu_down_read(&early_srcu);
+ srcu_up_read(&early_srcu, idx);
call_rcu(&head, test_callback);
early_srcu_cookie = start_poll_synchronize_srcu(&early_srcu);
call_srcu(&early_srcu, &shead, test_callback);
--
2.31.1.189.g2e36527f23