From patchwork Tue Nov 20 08:30:10 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 200253 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 593942C0097 for ; Tue, 20 Nov 2012 19:31:18 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752899Ab2KTIbD (ORCPT ); Tue, 20 Nov 2012 03:31:03 -0500 Received: from mail-ie0-f174.google.com ([209.85.223.174]:46901 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829Ab2KTIai (ORCPT ); Tue, 20 Nov 2012 03:30:38 -0500 Received: by mail-ie0-f174.google.com with SMTP id k13so8174101iea.19 for ; Tue, 20 Nov 2012 00:30:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=ZIiu57p+dkWkuLM/4kMNIZC1u2JlaDMYzU8QlW9VV/8=; b=GIkt9vpaJ+t4P/dNGksSu+FTFQ3PS+ZMzfrnJjUIjSTViHc7wnTeaSy6YtWDVpyZE/ 4d7okJZ8d6XYERbnMKd09c0CfVzQJBdY6hwzDWN1aZN1XpCKcZsmvTXFMyTQNhrJDft0 +fTWdSpQXGJbRvQHd8pe6wuZpn2eB8ue3F3P3w4nFx0fXp6fjYGejWkP0OmDIZQYrevr S6ObprTvV9huwpuhEmYUAPysOHxmX5X4+JFxs3exKeQQRnhyTgn7AQr2COWQ28pt4vaL Pm9dIpHoxS7++W5lPiWPtOAWy71K4DMaRbLPY7F4tNedoKi9dfFAU4cGOhwuyvamSzTy gX7A== Received: by 10.50.85.130 with SMTP id h2mr9123111igz.26.1353400238228; Tue, 20 Nov 2012 00:30:38 -0800 (PST) Received: from htj.dyndns.org.com (50-78-106-165-static.hfc.comcastbusiness.net. [50.78.106.165]) by mx.google.com with ESMTPS id uj6sm9933824igb.4.2012.11.20.00.30.35 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 20 Nov 2012 00:30:37 -0800 (PST) From: Tejun Heo To: daniel.wagner@bmw-carit.de, serge.hallyn@canonical.com, ebiederm@xmission.com, nhorman@tuxdriver.com, tgraf@suug.ch Cc: davem@davemloft.net, lizefan@huawei.com, cgroups@vger.kernel.org, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Tejun Heo Subject: [PATCH 6/7] netprio_cgroup: implement netprio[_set]_prio() helpers Date: Tue, 20 Nov 2012 00:30:10 -0800 Message-Id: <1353400211-5182-7-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1353400211-5182-1-git-send-email-tj@kernel.org> References: <1353400211-5182-1-git-send-email-tj@kernel.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Introduce two helpers - netprio_prio() and netprio_set_prio() - which hide the details of priomap access and expansion. This will help implementing hierarchy support. Signed-off-by: Tejun Heo Acked-by: Neil Horman --- net/core/netprio_cgroup.c | 72 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 50 insertions(+), 22 deletions(-) diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index 9409cdf..b2af0d0 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -87,6 +87,51 @@ static int extend_netdev_table(struct net_device *dev, u32 target_idx) return 0; } +/** + * netprio_prio - return the effective netprio of a cgroup-net_device pair + * @cgrp: cgroup part of the target pair + * @dev: net_device part of the target pair + * + * Should be called under RCU read or rtnl lock. + */ +static u32 netprio_prio(struct cgroup *cgrp, struct net_device *dev) +{ + struct netprio_map *map = rcu_dereference_rtnl(dev->priomap); + + if (map && cgrp->id < map->priomap_len) + return map->priomap[cgrp->id]; + return 0; +} + +/** + * netprio_set_prio - set netprio on a cgroup-net_device pair + * @cgrp: cgroup part of the target pair + * @dev: net_device part of the target pair + * @prio: prio to set + * + * Set netprio to @prio on @cgrp-@dev pair. Should be called under rtnl + * lock and may fail under memory pressure for non-zero @prio. + */ +static int netprio_set_prio(struct cgroup *cgrp, struct net_device *dev, + u32 prio) +{ + struct netprio_map *map; + int ret; + + /* avoid extending priomap for zero writes */ + map = rtnl_dereference(dev->priomap); + if (!prio && (!map || map->priomap_len <= cgrp->id)) + return 0; + + ret = extend_netdev_table(dev, cgrp->id); + if (ret) + return ret; + + map = rtnl_dereference(dev->priomap); + map->priomap[cgrp->id] = prio; + return 0; +} + static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) { struct cgroup_netprio_state *cs; @@ -105,14 +150,10 @@ static void cgrp_css_free(struct cgroup *cgrp) { struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp); struct net_device *dev; - struct netprio_map *map; rtnl_lock(); - for_each_netdev(&init_net, dev) { - map = rtnl_dereference(dev->priomap); - if (map && cgrp->id < map->priomap_len) - map->priomap[cgrp->id] = 0; - } + for_each_netdev(&init_net, dev) + WARN_ON_ONCE(netprio_set_prio(cgrp, dev, 0)); rtnl_unlock(); kfree(cs); } @@ -126,16 +167,10 @@ static int read_priomap(struct cgroup *cont, struct cftype *cft, struct cgroup_map_cb *cb) { struct net_device *dev; - u32 id = cont->id; - u32 priority; - struct netprio_map *map; rcu_read_lock(); - for_each_netdev_rcu(&init_net, dev) { - map = rcu_dereference(dev->priomap); - priority = (map && id < map->priomap_len) ? map->priomap[id] : 0; - cb->fill(cb, dev->name, priority); - } + for_each_netdev_rcu(&init_net, dev) + cb->fill(cb, dev->name, netprio_prio(cont, dev)); rcu_read_unlock(); return 0; } @@ -145,7 +180,6 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft, { char devname[IFNAMSIZ + 1]; struct net_device *dev; - struct netprio_map *map; u32 prio; int ret; @@ -158,14 +192,8 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft, rtnl_lock(); - ret = extend_netdev_table(dev, cgrp->id); - if (ret) - goto out_unlock; + ret = netprio_set_prio(cgrp, dev, prio); - map = rtnl_dereference(dev->priomap); - if (map) - map->priomap[cgrp->id] = prio; -out_unlock: rtnl_unlock(); dev_put(dev); return ret;