From patchwork Mon Feb 8 17:19:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 12076093 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E73C3C4332D for ; Mon, 8 Feb 2021 17:24:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B32F564E5A for ; Mon, 8 Feb 2021 17:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229795AbhBHRXz (ORCPT ); Mon, 8 Feb 2021 12:23:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:34782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233919AbhBHRVQ (ORCPT ); Mon, 8 Feb 2021 12:21:16 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DE90064EB4; Mon, 8 Feb 2021 17:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612804782; bh=4mWavSQrebp/ovnVdSJxGHCsK1N5UL37VgY1dObRWBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XoRptTY3lHuNhszm59ar1AedE8RBobWBi60tht1sn84kHiyL6F5KTswztN2POqJ/I rUzitizraiA7IDm9hG52FhNSqdu+BP5b46bHn7hBEQS1he3lORgzowTDtiJw41N6ne ynLDmilW0jfxR+HpBh/mIMnN7xbSXeLeEuuNg/STKRmDw4FKGeGQNrYDmt3Gtb2lAw SB5DifWfHvzp/uRKf+3/qlNPHEaGNZ7o8m0MO1GhSVJlJhPIXKufuStJhOAYBIqdJo WuK54+1CsHX097V5tqwhNOL2e1MdCvyQSDLJdd5nEFA4qcB10a1KFX/3etLTV2TUEu t2YFrYEJHmh6A== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, alexander.duyck@gmail.com Cc: Antoine Tenart , netdev@vger.kernel.org Subject: [PATCH net-next v2 09/12] net-sysfs: remove the rtnl lock when accessing the xps maps Date: Mon, 8 Feb 2021 18:19:14 +0100 Message-Id: <20210208171917.1088230-10-atenart@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210208171917.1088230-1-atenart@kernel.org> References: <20210208171917.1088230-1-atenart@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Now that nr_ids and num_tc are stored in the xps dev_maps, which are RCU protected, we do not have the need to protect the xps_cpus_show and xps_rxqs_show functions with the rtnl lock. Signed-off-by: Antoine Tenart --- net/core/net-sysfs.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index c2276b589cfb..6ce5772e799e 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1328,17 +1328,12 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue, index = get_netdev_queue_index(queue); - if (!rtnl_trylock()) - return restart_syscall(); - /* If queue belongs to subordinate dev use its map */ dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) { - ret = -EINVAL; - goto err_rtnl_unlock; - } + if (tc < 0) + return -EINVAL; rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_maps[XPS_CPUS]); @@ -1371,16 +1366,12 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue, out_no_maps: rcu_read_unlock(); - rtnl_unlock(); - len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids); bitmap_free(mask); return len < PAGE_SIZE ? len : -EINVAL; err_rcu_unlock: rcu_read_unlock(); -err_rtnl_unlock: - rtnl_unlock(); return ret; } @@ -1435,14 +1426,9 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) index = get_netdev_queue_index(queue); - if (!rtnl_trylock()) - return restart_syscall(); - tc = netdev_txq_to_tc(dev, index); - if (tc < 0) { - ret = -EINVAL; - goto err_rtnl_unlock; - } + if (tc < 0) + return -EINVAL; rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_maps[XPS_RXQS]); @@ -1475,8 +1461,6 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) out_no_maps: rcu_read_unlock(); - rtnl_unlock(); - len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids); bitmap_free(mask); @@ -1484,8 +1468,6 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) err_rcu_unlock: rcu_read_unlock(); -err_rtnl_unlock: - rtnl_unlock(); return ret; }