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authorFrederic Weisbecker <frederic@kernel.org>2021-04-14 15:24:13 +0200
committerPaul E. McKenney <paulmck@kernel.org>2021-05-12 12:12:33 -0700
commit0a580fa65cfa08a40af1a0a2cf73d100863e4981 (patch)
tree3f3137481a8ff1d4a367b0bfcd4e042b890d4195 /kernel/rcu/update.c
parentb5befe842e6612cf894cf4a199924ee872d8b7d8 (diff)
srcu: Early test SRCU polling start
Place an early call to start_poll_synchronize_srcu() before the invocation of call_srcu() on the same srcu_struct structure. After the later call to srcu_barrier(), the completion of the first grace period should be visible to a subsequent invocation of poll_state_synchronize_srcu(), and if not, warn. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/update.c')
-rw-r--r--kernel/rcu/update.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index b95ae86c40a7..0aa118ac37ba 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -524,6 +524,7 @@ static void test_callback(struct rcu_head *r)
}
DEFINE_STATIC_SRCU(early_srcu);
+static unsigned long early_srcu_cookie;
struct early_boot_kfree_rcu {
struct rcu_head rh;
@@ -536,8 +537,10 @@ static void early_boot_test_call_rcu(void)
struct early_boot_kfree_rcu *rhp;
call_rcu(&head, test_callback);
- if (IS_ENABLED(CONFIG_SRCU))
+ if (IS_ENABLED(CONFIG_SRCU)) {
+ early_srcu_cookie = start_poll_synchronize_srcu(&early_srcu);
call_srcu(&early_srcu, &shead, test_callback);
+ }
rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
if (!WARN_ON_ONCE(!rhp))
kfree_rcu(rhp, rh);
@@ -563,6 +566,7 @@ static int rcu_verify_early_boot_tests(void)
if (IS_ENABLED(CONFIG_SRCU)) {
early_boot_test_counter++;
srcu_barrier(&early_srcu);
+ WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie));
}
}
if (rcu_self_test_counter != early_boot_test_counter) {