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From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	rostedt@goodmis.org,
	"Joel Fernandes (Google)" <joel@joelfernandes.org>,
	"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 14/14] rxrpc: Use call_rcu_flush() instead of call_rcu()
Date: Wed, 19 Oct 2022 15:51:44 -0700	[thread overview]
Message-ID: <20221019225144.2500095-14-paulmck@kernel.org> (raw)
In-Reply-To: <20221019225138.GA2499943@paulmck-ThinkPad-P17-Gen-1>

From: "Joel Fernandes (Google)" <joel@joelfernandes.org>

call_rcu() changes to save power may cause slowness. Use the
call_rcu_flush() API instead which reverts to the old behavior.

We find this via inspection that the RCU callback does a wakeup of a
thread. This usually indicates that something is waiting on it. To be
safe, let us use call_rcu_flush() here instead.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 net/rxrpc/conn_object.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 22089e37e97f0..fdcfb509cc443 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -253,7 +253,7 @@ void rxrpc_kill_connection(struct rxrpc_connection *conn)
 	 * must carry a ref on the connection to prevent us getting here whilst
 	 * it is queued or running.
 	 */
-	call_rcu(&conn->rcu, rxrpc_destroy_connection);
+	call_rcu_flush(&conn->rcu, rxrpc_destroy_connection);
 }
 
 /*
-- 
2.31.1.189.g2e36527f23


      parent reply	other threads:[~2022-10-19 22:52 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-19 22:51 [PATCH rcu 0/14] Lazy call_rcu() updates for v6.2 Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 01/14] rcu: Simplify rcu_init_nohz() cpumask handling Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 02/14] rcu: Fix late wakeup when flush of bypass cblist happens Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 03/14] rcu: Fix missing nocb gp wake on rcu_barrier() Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 04/14] rcu: Make call_rcu() lazy to save power Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 05/14] rcu: Refactor code a bit in rcu_nocb_do_flush_bypass() Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 06/14] rcu: Shrinker for lazy rcu Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 07/14] rcuscale: Add laziness and kfree tests Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 08/14] percpu-refcount: Use call_rcu_flush() for atomic switch Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 09/14] rcu/sync: Use call_rcu_flush() instead of call_rcu Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 10/14] rcu/rcuscale: Use call_rcu_flush() for async reader test Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 11/14] rcu/rcutorture: Use call_rcu_flush() where needed Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 12/14] scsi/scsi_error: Use call_rcu_flush() instead of call_rcu() Paul E. McKenney
2022-10-19 22:51 ` [PATCH rcu 13/14] workqueue: Make queue_rcu_work() use call_rcu_flush() Paul E. McKenney
2022-10-24  0:36   ` Joel Fernandes
2022-10-24  3:15     ` Paul E. McKenney
2022-10-24 10:49       ` Uladzislau Rezki
2022-10-24 12:23         ` Uladzislau Rezki
2022-10-24 14:31           ` Joel Fernandes
2022-10-24 15:39             ` Paul E. McKenney
2022-10-24 16:25               ` Uladzislau Rezki
2022-10-24 16:48                 ` Paul E. McKenney
2022-10-24 16:55                   ` Uladzislau Rezki
2022-10-24 17:08                     ` Uladzislau Rezki
2022-10-24 17:20                       ` Joel Fernandes
2022-10-24 17:35                         ` Paul E. McKenney
2022-10-24 20:12                           ` Joel Fernandes
2022-10-24 20:16                             ` Joel Fernandes
2022-10-25 10:48                               ` Uladzislau Rezki
2022-10-25 15:05                                 ` Joel Fernandes
2022-10-26 20:35                                   ` Uladzislau Rezki
2022-10-24 20:19                             ` Paul E. McKenney
2022-10-24 20:26                               ` Joel Fernandes
2022-10-24 17:40                         ` Uladzislau Rezki
2022-10-24 20:08                           ` Joel Fernandes
2022-10-25 10:47                             ` Uladzislau Rezki
2022-10-28 21:23                   ` Joel Fernandes
2022-10-28 21:42                     ` Joel Fernandes
2022-10-31 13:21                     ` Uladzislau Rezki
2022-10-31 13:37                       ` Joel Fernandes
2022-10-31 18:15                       ` Joel Fernandes
2022-11-01  4:49                         ` Uladzislau Rezki
2022-10-24 16:54                 ` Joel Fernandes
2022-10-19 22:51 ` Paul E. McKenney [this message]

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