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From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, frederic@kernel.org,
	paulmck@kernel.org,
	"Joel Fernandes (Google)" <joel@joelfernandes.org>
Subject: [PATCH v9 12/13] rxrpc: Use call_rcu_flush() instead of call_rcu()
Date: Sun, 16 Oct 2022 16:23:04 +0000	[thread overview]
Message-ID: <20221016162305.2489629-13-joel@joelfernandes.org> (raw)
In-Reply-To: <20221016162305.2489629-1-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>
---
 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 22089e37e97f..fdcfb509cc44 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);
 }
 
 /*
-- 
2.38.0.413.g74048e4d9e-goog


  parent reply	other threads:[~2022-10-16 16:24 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-16 16:22 [PATCH v9 00/13] rcu: call_rcu() power improvements Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 01/13] rcu: Fix missing nocb gp wake on rcu_barrier() Joel Fernandes (Google)
2022-10-16 16:25   ` Joel Fernandes
2022-10-16 18:23     ` Paul E. McKenney
2022-10-16 16:22 ` [PATCH v9 02/13] rcu: Make call_rcu() lazy to save power Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 03/13] rcu: Refactor code a bit in rcu_nocb_do_flush_bypass() Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 04/13] rcu: shrinker for lazy rcu Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 05/13] rcuscale: Add laziness and kfree tests Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 06/13] percpu-refcount: Use call_rcu_flush() for atomic switch Joel Fernandes (Google)
2022-10-16 16:22 ` [PATCH v9 07/13] rcu/sync: Use call_rcu_flush() instead of call_rcu Joel Fernandes (Google)
2022-10-16 16:23 ` [PATCH v9 08/13] rcu/rcuscale: Use call_rcu_flush() for async reader test Joel Fernandes (Google)
2022-10-16 16:23 ` [PATCH v9 09/13] rcu/rcutorture: Use call_rcu_flush() where needed Joel Fernandes (Google)
2022-10-16 16:23 ` [PATCH v9 10/13] scsi/scsi_error: Use call_rcu_flush() instead of call_rcu() Joel Fernandes (Google)
2022-10-16 16:23 ` [PATCH v9 11/13] workqueue: Make queue_rcu_work() use call_rcu_flush() Joel Fernandes (Google)
2022-10-16 16:23 ` Joel Fernandes (Google) [this message]
2022-10-16 16:23 ` [PATCH v9 13/13] rcu/debug: Add wake-up debugging for lazy callbacks Joel Fernandes (Google)
2022-10-17 13:37 ` [PATCH v9 00/13] rcu: call_rcu() power improvements Paul E. McKenney
2022-10-17 13:47   ` Joel Fernandes
2022-10-17 14:07     ` Paul E. McKenney

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