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 D4C94360EF2; Mon, 14 Sep 2026 03:37:26 +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=1789357048; cv=none; b=PRy/cWC54BnsaE+C3BAmA4Relgvymu/pnPFuWk8wAtQFPkMvyTzv9N053zbv9SP8rDf2FLpo8TkxZwm9lwdZnJPQk4nvn2mXSw+RKhBPZN2HGInzj1LLlAMUFsspCS715eGZOpiZV3FVxPp0nC8RieCwzQ7SvkCyvEeZPjs/TIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789357048; c=relaxed/simple; bh=IvXMUudo4vfx/gOC1IrVVgdp9B6SuF91cGN/4R4bEt0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JHEiMl0Q7V2c0dE3BRtP1DFKNjmfFxWQFZ9CIrnBE4/fNmu93TSLEJ/hQnSXG9ejd15Tly2ySUz+so/kidemsPJ9TGhYRAozyA22Vwo8a9sAtLg/wzG3JoQJUHpjXncB7c4no3UJPksdQZchYJQPOnrfQfqC5lyFFHX1ScradRA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cf/sPe8w; 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="Cf/sPe8w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64EEC1F000FF; Mon, 14 Sep 2026 03:37:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789357046; bh=pgSaccr31vvq36fpdiyaqN5ENIPd6m7tZyd54+RlfVQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Cf/sPe8wfmbyhVU17magYCemA2ZT0snauNkoCCY61lOI8Rp38PqZevtcc0LZ1M0Nw rJUn9mc8YezxgMUQwms8n9PJQPuwegOrAzEHEQkQTAZqmQQdn6Wrc20zMD+veWzXmZ 94ZsC52M1nkGZLxbuSUaHHbCgVplIHvCZD2zcI8mBW5oK+ETFR0PrLg02DkwAeK28o oqUZT1isBwzP8lrqpFVz0wftxSa+O1L4OIcg1ajHTCB1wj4u/zTsVHGfZaO2Y7b6Jq z1yYmprXt0nbXlZtgf7Samw+LglxVqb3P2r3nXMkUp+RqXXxAaRpnCED5ZWraUBqKy oR39WfCXVkp/w== 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 v3 12/13] net/rds: drop rds_conn_count in favor of t_conn_count Date: Sun, 13 Sep 2026 20:37:18 -0700 Message-Id: <20260914033719.138057-13-achender@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260914033719.138057-1-achender@kernel.org> References: <20260914033719.138057-1-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 e5a8534c23cf..f5f25e4a53b9 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]; @@ -332,12 +331,13 @@ 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; } @@ -408,7 +408,6 @@ 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 { @@ -431,7 +430,6 @@ 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); } } @@ -669,7 +667,6 @@ 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++) @@ -678,10 +675,6 @@ 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