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 6A24B352C34; Sat, 12 Sep 2026 03:50:33 +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=1789185034; cv=none; b=LVJ1nMADt/0m6+bI7A4jxTdbY50mgjBO7ofyWvFoBXd8Hsq7AkXTZ6Xh0aT0P6n8G0r2TEPCE/Mypmnx+tyLgsWV8bLY+DmroKLytnKOwryohhB+H19TwKh5uaYXRlse3qedxpUsOcvD3ZI+YNNmew13wQaILGd+YWSLkHv9X4s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789185034; c=relaxed/simple; bh=YE8oK1jxwKg30sG60N4uz48eav9AFIPyK+vAmCQfvyM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XyftUnLq8i1yGt/kEr+UB2N+ve1R7Z0qQjYqDRLMcybNVWDg3F1hkFL8gnLLW1hrrexlQX5379R8P6wCyXDjuySlcEq8/lUQLMfVHR/ugJj5j4GJToURUuHnB42xLqRpkTReOLVA8EZ9/r17vStEs5W/+4wqQ5e6BsZHVu0V7Wo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j7QdYw2o; 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="j7QdYw2o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B34D01F0089B; Sat, 12 Sep 2026 03:50:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789185033; bh=PJTZnV2oJVF7I2WWghJlykt04t0F8no9orj3aLhOU2U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=j7QdYw2osXoWWQLcqjo5nDDruxlmR6Q2eysyy66wxp/6GiLX7r4Z91mHDOX4RNvi8 NgDNpGo2Qj+GABN2dEjkdL9NF7qWQeHXT+K4v9DVZKe+rg+aaHzB4md2/3nKmnznPi tVbkiQIuBNIB74v3ndXrWs5MSYZUq1pkQ+33lXeEyrchMsK1Zrgnml85xVzE+xiWvl ukfBz17bAY9bBy+iAfkfgvfkFMHLOp8oWVFQ9YltST9QA3bgGgWXDYI9vaKUuQNktb /4xglkOuIJjIWgVO6MqZ00N07ZPxvUklqYhNLvnaqxPcbgk+azCfOatePo8gTRov64 TK77Lv+dcoabQ== 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, nicoyip.dev@gmail.com Subject: [PATCH net-next v2 8/9] net/rds: drop rds_conn_count in favor of t_conn_count Date: Fri, 11 Sep 2026 20:50:26 -0700 Message-Id: <20260912035027.27447-9-achender@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260912035027.27447-1-achender@kernel.org> References: <20260912035027.27447-1-achender@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The previous patch 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, leaving the free path lock-free. 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 1ec141d6faa3..11813f93961d 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]; @@ -316,12 +315,13 @@ 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; } @@ -392,7 +392,6 @@ 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 { @@ -426,7 +425,6 @@ 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); } } @@ -656,7 +654,6 @@ 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++) @@ -665,10 +662,6 @@ 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