From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
mingo@kernel.org, jiangshanlai@gmail.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
Frederic Weisbecker <frederic@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Neeraj Upadhyay <neeraju@codeaurora.org>,
Uladzislau Rezki <urezki@gmail.com>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH tip/core/rcu 6/6] srcu: Early test SRCU polling start
Date: Tue, 11 May 2021 16:07:45 -0700 [thread overview]
Message-ID: <20210511230745.2894650-6-paulmck@kernel.org> (raw)
In-Reply-To: <20210511230720.GA2894512@paulmck-ThinkPad-P17-Gen-1>
From: Frederic Weisbecker <frederic@kernel.org>
Place an early call to start_poll_synchronize_srcu() before the 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>
---
kernel/rcu/update.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
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) {
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2021-05-11 23:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 23:07 [PATCH tip/core/rcu 0/6] SRCU updates for v5.14 Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 1/6] srcu: Remove superfluous sdp->srcu_lock_count zero filling Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 2/6] srcu: Remove superfluous ssp initialization for early callbacks Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 3/6] srcu: Unconditionally embed struct lockdep_map Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 4/6] srcu: Initialize SRCU after timers Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 5/6] srcu: Fix broken node geometry after early ssp init Paul E. McKenney
2021-05-11 23:07 ` Paul E. McKenney [this message]
2021-05-11 23:09 ` [PATCH tip/core/rcu 1/4] rcu-tasks: Add block comment laying out RCU Tasks design Paul E. McKenney
2021-05-11 23:09 ` [PATCH tip/core/rcu 2/4] rcu-tasks: Add block comment laying out RCU Rude design Paul E. McKenney
2021-05-11 23:09 ` [PATCH tip/core/rcu 3/4] rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states Paul E. McKenney
2021-05-11 23:09 ` [PATCH tip/core/rcu 4/4] tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline Paul E. McKenney
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