From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C62153AE6FC; Thu, 8 Oct 2026 03:13:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791429222; cv=none; b=sXyRA/PVXRcISgNDqLGUC7+eFDlGod4UnPvDTkHdYnyDQyxmVEjtR8wADBRCSvISVCXCV9FiIY1dpl+cJKKdyqbTrMAog7OwJK0rQw5lJWtTWf+LPwBaWCkjnLIWNWmOyVeVKK4mr7k3HadxAXy3II2B9qDyeDXyot25AyvMK0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791429222; c=relaxed/simple; bh=7rWMTNKDNLBbmb+h/nkRosnrwrNG/Hc8yWk7scsI65I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=MeTEqW1Tv6I3xL0hVQcqM5CM94qlOGdGc6X5qPke+wSZfM1rC6wP+eL9Q4hzVmnaPO5fvEWXfGc2j5/sW73R1yaQ+eTikzHnLrsZLoaUXdssMBTNlZTBSeNtqoMEQRXi+mzjkJ+lo+tirgBCJ9P8vQ2fPBH35UtE9redJdwoe/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AfJitT+k; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AfJitT+k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60DC21F00899; Thu, 8 Oct 2026 03:13:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791429220; bh=vsgT4EegZshDoVvMGK9Sk20PzYAQop1qCYh2ThW3v/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AfJitT+kYUgrgdyD+WgNYaRsCqLfDrkTpswMI1A00AFqo57rBtaWbelr4sZY0vNLZ HZNuZdbJmZoOyWp7R6cKjbKnpD0oNg9zugd8sfntBnC8Y0xl/Jjv4mp4nh0WjCfbZR dpckKleGPhfVUZTcW7ZKwkbu/9z9xMMu4R1trt8Lt8hDHGzND50Erjg66556n3p+oh rK7pBwVg+zJo8gRyDRZZuh9ARWIJE7ESiwqrd3axoR5lpCZ02WtWN/jdx95EB2q8Op 8fdWzoF2mh45C7S1NLLwDrCRCABvs129BrJB1x/IiYrJ2TooINOqxEpxKylhCqzmAD KPjCXGg6HSdPA== From: Allison Henderson To: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, pabeni@redhat.com, edumazet@google.com, kuba@kernel.org, horms@kernel.org Cc: achender@kernel.org Subject: [PATCH net-next v9 13/13] net/rds: drop rds_conn_count in favor of t_conn_count Date: Wed, 7 Oct 2026 20:13:33 -0700 Message-Id: <20261008031333.1142174-14-achender@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20261008031333.1142174-1-achender@kernel.org> References: <20261008031333.1142174-1-achender@kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The patch "net/rds: wait for connections to be freed on transport unload", earlier in this series, gave each transport its own connection count in t_conn_count, incremented and decremented at exactly the points where the global rds_conn_count is. That leaves rds_conn_count with a single remaining consumer: the seed of the per-path workqueue names in __rds_conn_create(). Switch the name seed to t_conn_count, as UEK does, and remove rds_conn_count. The numbering becomes per-transport instead of global, so connections of different transports can now receive the same seed; workqueue names carry no uniqueness requirement, and the seed was already reused as the count rose and fell. Removing the counter also removes the rds_conn_lock round-trip that rds_conn_destroy_fini() took solely to decrement it. (The free path still sleeps in destroy_workqueue(), so the last reference has to be dropped from process context as before; only that one lock goes.) Based on the Oracle UEK commit "net/rds: Each RDS transport should keep its own connection count". Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson --- net/rds/connection.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/net/rds/connection.c b/net/rds/connection.c index 7d03d53a3101..8c4df7d6b294 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -47,7 +47,6 @@ /* converting this to RCU is a chore for another day.. */ static DEFINE_SPINLOCK(rds_conn_lock); -static unsigned long rds_conn_count; /* woken whenever a transport's t_conn_count drops to zero */ static DECLARE_WAIT_QUEUE_HEAD(rds_conn_freed_waitq); static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES]; @@ -338,12 +337,13 @@ static struct rds_connection *__rds_conn_create(struct net *net, init_waitqueue_head(&conn->c_hs_waitq); for (i = 0; i < npaths; i++) { + int seq = atomic_read(&trans->t_conn_count); + __rds_conn_path_init(conn, &conn->c_path[i], is_outgoing); conn->c_path[i].cp_index = i; conn->c_path[i].cp_wq = - alloc_ordered_workqueue("krds_cp_wq#%lu/%d", 0, - rds_conn_count, i); + alloc_ordered_workqueue("krds_cp_wq#%d/%d", 0, seq, i); if (!conn->c_path[i].cp_wq) conn->c_path[i].cp_wq = rds_wq; } @@ -412,7 +412,6 @@ static struct rds_connection *__rds_conn_create(struct net *net, rds_conn_get(conn); /* caller */ rcu_assign_pointer(parent->c_passive, conn); rds_cong_add_conn(conn); - rds_conn_count++; atomic_inc(&conn->c_trans->t_conn_count); } } else { @@ -435,7 +434,6 @@ static struct rds_connection *__rds_conn_create(struct net *net, rds_conn_get(conn); hlist_add_head_rcu(&conn->c_hash_node, head); rds_cong_add_conn(conn); - rds_conn_count++; atomic_inc(&conn->c_trans->t_conn_count); } } @@ -684,7 +682,6 @@ static void rds_conn_destroy_fini(struct kref *kref) c_refcount); int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1); struct rds_transport *trans = conn->c_trans; - unsigned long flags; int i; for (i = 0; i < npaths; i++) @@ -693,10 +690,6 @@ static void rds_conn_destroy_fini(struct kref *kref) kfree(conn->c_path); kmem_cache_free(rds_conn_slab, conn); - spin_lock_irqsave(&rds_conn_lock, flags); - rds_conn_count--; - spin_unlock_irqrestore(&rds_conn_lock, flags); - /* only after everything the transport module owns has been * freed above may its unload proceed */ -- 2.25.1