Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752926Ab2KTIbE (ORCPT ); Tue, 20 Nov 2012 03:31:04 -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 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3861 Lines: 134 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; -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/