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From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     rcu@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, kernel-team@meta.com,
        rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 1/6] rcu: Update synchronize_rcu_mult() comment for call_rcu_hurry()
Date:   Mon, 17 Jul 2023 11:03:12 -0700
Message-Id: <20230717180317.1097590-1-paulmck@kernel.org>
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Those who have worked with RCU for some time will naturally think in
terms of the long-standing call_rcu() API rather than the much newer
call_rcu_hurry() API.  But it is call_rcu_hurry() that you should normally
pass to synchronize_rcu_mult().  This commit therefore updates the header
comment to point this out.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 include/linux/rcupdate_wait.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/rcupdate_wait.h b/include/linux/rcupdate_wait.h
index 699b938358bf..5e0f74f2f8ca 100644
--- a/include/linux/rcupdate_wait.h
+++ b/include/linux/rcupdate_wait.h
@@ -42,6 +42,11 @@ do {									\
  * call_srcu() function, with this wrapper supplying the pointer to the
  * corresponding srcu_struct.
  *
+ * Note that call_rcu_hurry() should be used instead of call_rcu()
+ * because in kernels built with CONFIG_RCU_LAZY=y the delay between the
+ * invocation of call_rcu() and that of the corresponding RCU callback
+ * can be multiple seconds.
+ *
  * The first argument tells Tiny RCU's _wait_rcu_gp() not to
  * bother waiting for RCU.  The reason for this is because anywhere
  * synchronize_rcu_mult() can be called is automatically already a full
-- 
2.40.1