From patchwork Mon Dec 21 19:36:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 346935 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=-17.0 required=3.0 tests=BAYES_00, 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 B45A6C433DB for ; Mon, 21 Dec 2020 19:37:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8329522BE9 for ; Mon, 21 Dec 2020 19:37:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726302AbgLUThf (ORCPT ); Mon, 21 Dec 2020 14:37:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:59606 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725783AbgLUThe (ORCPT ); Mon, 21 Dec 2020 14:37:34 -0500 From: Antoine Tenart Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: davem@davemloft.net, kuba@kernel.org, alexander.duyck@gmail.com Cc: Antoine Tenart , netdev@vger.kernel.org, pabeni@redhat.com Subject: [PATCH net v2 2/3] net: move the xps cpus retrieval out of net-sysfs Date: Mon, 21 Dec 2020 20:36:43 +0100 Message-Id: <20201221193644.1296933-3-atenart@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201221193644.1296933-1-atenart@kernel.org> References: <20201221193644.1296933-1-atenart@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Accesses to dev->xps_cpus_map (when using dev->num_tc) should be protected by the xps_map mutex, to avoid possible race conditions when dev->num_tc is updated while the map is accessed. This patch moves the logic accessing dev->xps_cpu_map and dev->num_tc to net/core/dev.c, where the xps_map mutex is defined and used. Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes") Signed-off-by: Antoine Tenart --- include/linux/netdevice.h | 8 ++++++ net/core/dev.c | 59 +++++++++++++++++++++++++++++++++++++++ net/core/net-sysfs.c | 54 ++++++++--------------------------- 3 files changed, 79 insertions(+), 42 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 259be67644e3..bfd6cfa3ea90 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3671,6 +3671,8 @@ int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask, u16 index); int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask, u16 index, bool is_rxqs_map); +int netif_show_xps_queue(struct net_device *dev, unsigned long **mask, + u16 index); /** * netif_attr_test_mask - Test a CPU or Rx queue set in a mask @@ -3769,6 +3771,12 @@ static inline int __netif_set_xps_queue(struct net_device *dev, { return 0; } + +static inline int netif_show_xps_queue(struct net_device *dev, + unsigned long **mask, u16 index) +{ + return 0; +} #endif /** diff --git a/net/core/dev.c b/net/core/dev.c index effdb7fee9df..a0257da4160a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2831,6 +2831,65 @@ int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask, } EXPORT_SYMBOL(netif_set_xps_queue); +int netif_show_xps_queue(struct net_device *dev, unsigned long **mask, + u16 index) +{ + const unsigned long *possible_mask = NULL; + int j, num_tc = 1, tc = 0, ret = 0; + struct xps_dev_maps *dev_maps; + unsigned int nr_ids; + + rcu_read_lock(); + mutex_lock(&xps_map_mutex); + + if (dev->num_tc) { + num_tc = dev->num_tc; + if (num_tc < 0) { + ret = -EINVAL; + goto out_no_map; + } + + /* 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 out_no_map; + } + } + + dev_maps = rcu_dereference(dev->xps_cpus_map); + if (!dev_maps) + goto out_no_map; + nr_ids = nr_cpu_ids; + if (num_possible_cpus() > 1) + possible_mask = cpumask_bits(cpu_possible_mask); + + for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids), + j < nr_ids;) { + int i, tci = j * num_tc + tc; + struct xps_map *map; + + map = rcu_dereference(dev_maps->attr_map[tci]); + if (!map) + continue; + + for (i = map->len; i--;) { + if (map->queues[i] == index) { + set_bit(j, *mask); + break; + } + } + } + +out_no_map: + mutex_unlock(&xps_map_mutex); + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL(netif_show_xps_queue); #endif static void __netdev_unbind_sb_channel(struct net_device *dev, diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 999b70c59761..29ee69b67972 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1314,60 +1314,30 @@ static const struct attribute_group dql_group = { #endif /* CONFIG_BQL */ #ifdef CONFIG_XPS -static ssize_t xps_cpus_show(struct netdev_queue *queue, - char *buf) +static ssize_t xps_cpus_show(struct netdev_queue *queue, char *buf) { struct net_device *dev = queue->dev; - int cpu, len, num_tc = 1, tc = 0; - struct xps_dev_maps *dev_maps; - cpumask_var_t mask; - unsigned long index; + unsigned long *mask, index; + int len, ret; if (!netif_is_multiqueue(dev)) return -ENOENT; index = get_netdev_queue_index(queue); - if (dev->num_tc) { - /* Do not allow XPS on subordinate device directly */ - num_tc = dev->num_tc; - if (num_tc < 0) - return -EINVAL; - - /* 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) - return -EINVAL; - } - - if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) + mask = bitmap_zalloc(nr_cpu_ids, GFP_KERNEL); + if (!mask) return -ENOMEM; - rcu_read_lock(); - dev_maps = rcu_dereference(dev->xps_cpus_map); - if (dev_maps) { - for_each_possible_cpu(cpu) { - int i, tci = cpu * num_tc + tc; - struct xps_map *map; - - map = rcu_dereference(dev_maps->attr_map[tci]); - if (!map) - continue; - - for (i = map->len; i--;) { - if (map->queues[i] == index) { - cpumask_set_cpu(cpu, mask); - break; - } - } - } + ret = netif_show_xps_queue(dev, &mask, index); + if (ret) { + bitmap_free(mask); + return ret; } - rcu_read_unlock(); - len = snprintf(buf, PAGE_SIZE, "%*pb\n", cpumask_pr_args(mask)); - free_cpumask_var(mask); + len = bitmap_print_to_pagebuf(false, buf, mask, nr_cpu_ids); + bitmap_free(mask); + return len < PAGE_SIZE ? len : -EINVAL; }