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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,
	Frederic Weisbecker <frederic@kernel.org>,
	"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 1/4] rcu/nocb: Fix segcblist state machine comments about bypass
Date: Tue,  4 Jun 2024 15:28:22 -0700
Message-Id: <20240604222825.2371133-1-paulmck@kernel.org>
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From: Frederic Weisbecker <frederic@kernel.org>

The parts explaining the bypass lifecycle in (de-)offloading are out
of date and/or wrong. Bypass is simply enabled whenever SEGCBLIST_RCU_CORE
flag is off.

Fix the comments accordingly.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 include/linux/rcu_segcblist.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h
index 659d13a7ddaaa..1e5b4ef167caa 100644
--- a/include/linux/rcu_segcblist.h
+++ b/include/linux/rcu_segcblist.h
@@ -141,7 +141,7 @@ struct rcu_cblist {
  *  |                           SEGCBLIST_KTHREAD_GP                           |
  *  |                                                                          |
  *  |   CB/GP kthreads handle callbacks holding nocb_lock, local rcu_core()    |
- *  |   handles callbacks concurrently. Bypass enqueue is enabled.             |
+ *  |   handles callbacks concurrently. Bypass enqueue is disabled.            |
  *  |   Invoke RCU core so we make sure not to preempt it in the middle with   |
  *  |   leaving some urgent work unattended within a jiffy.                    |
  *  ----------------------------------------------------------------------------
@@ -154,8 +154,7 @@ struct rcu_cblist {
  *  |                           SEGCBLIST_KTHREAD_GP                           |
  *  |                                                                          |
  *  |   CB/GP kthreads and local rcu_core() handle callbacks concurrently      |
- *  |   holding nocb_lock. Wake up CB and GP kthreads if necessary. Disable    |
- *  |   bypass enqueue.                                                        |
+ *  |   holding nocb_lock. Wake up CB and GP kthreads if necessary.            |
  *  ----------------------------------------------------------------------------
  *                                      |
  *                                      v
@@ -185,7 +184,7 @@ struct rcu_cblist {
  *  |                                                                          |
  *  | Callbacks processed by rcu_core() from softirqs or local                 |
  *  | rcuc kthread, while holding nocb_lock. Forbid nocb_timer to be armed.    |
- *  | Flush pending nocb_timer. Flush nocb bypass callbacks.                   |
+ *  | Flush pending nocb_timer.                                                |
  *  ----------------------------------------------------------------------------
  *                                      |
  *                                      v
-- 
2.40.1