From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752446Ab2KTI5S (ORCPT ); Tue, 20 Nov 2012 03:57:18 -0500 Received: from hotel311.server4you.de ([85.25.146.15]:51317 "EHLO hotel311.server4you.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751520Ab2KTI5R (ORCPT ); Tue, 20 Nov 2012 03:57:17 -0500 Message-ID: <50AB45EA.2050507@monom.org> Date: Tue, 20 Nov 2012 09:57:14 +0100 From: Daniel Wagner User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Tejun Heo CC: serge.hallyn@canonical.com, ebiederm@xmission.com, nhorman@tuxdriver.com, tgraf@suug.ch, davem@davemloft.net, lizefan@huawei.com, cgroups@vger.kernel.org, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 7/7] netprio_cgroup: allow nesting and inherit config on cgroup creation References: <1353400211-5182-1-git-send-email-tj@kernel.org> <1353400211-5182-8-git-send-email-tj@kernel.org> In-Reply-To: <1353400211-5182-8-git-send-email-tj@kernel.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tejun, On 20.11.2012 09:30, Tejun Heo wrote: > Inherit netprio configuration from ->css_online(), allow nesting and > remove .broken_hierarchy marking. This makes netprio_cgroup's > behavior match netcls_cgroup's. > > Note that this patch changes userland-visible behavior. Nesting is > allowed and the first level cgroups below the root cgroup behave > differently - they inherit priorities from the root cgroup on creation > instead of starting with 0. This is unfortunate but not doing so is > much crazier. > > Signed-off-by: Tejun Heo Tested and Acked-by: Daniel Wagner > --- > Documentation/cgroups/net_prio.txt | 2 ++ > net/core/netprio_cgroup.c | 42 ++++++++++++++++++++++---------------- > 2 files changed, 26 insertions(+), 18 deletions(-) > > diff --git a/Documentation/cgroups/net_prio.txt b/Documentation/cgroups/net_prio.txt > index 01b3226..a82cbd2 100644 > --- a/Documentation/cgroups/net_prio.txt > +++ b/Documentation/cgroups/net_prio.txt > @@ -51,3 +51,5 @@ One usage for the net_prio cgroup is with mqprio qdisc allowing application > traffic to be steered to hardware/driver based traffic classes. These mappings > can then be managed by administrators or other networking protocols such as > DCBX. > + > +A new net_prio cgroup inherits the parent's configuration. > diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c > index b2af0d0..bde53da 100644 > --- a/net/core/netprio_cgroup.c > +++ b/net/core/netprio_cgroup.c > @@ -136,9 +136,6 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) > { > struct cgroup_netprio_state *cs; > > - if (cgrp->parent && cgrp->parent->id) > - return ERR_PTR(-EINVAL); > - > cs = kzalloc(sizeof(*cs), GFP_KERNEL); > if (!cs) > return ERR_PTR(-ENOMEM); > @@ -146,16 +143,34 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) > return &cs->css; > } > > -static void cgrp_css_free(struct cgroup *cgrp) > +static int cgrp_css_online(struct cgroup *cgrp) > { > - struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp); > + struct cgroup *parent = cgrp->parent; > struct net_device *dev; > + int ret = 0; > + > + if (!parent) > + return 0; BTW, parent is always != NULL, because the root cgroup will be attached to the dummytop cgroup. This is the reason why there are this check in netprio_prio() 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]; is necessary. cheer, daniel