From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: Re: [PATCH 7/7] netprio_cgroup: allow nesting and inherit config on cgroup creation Date: Tue, 20 Nov 2012 09:57:14 +0100 Message-ID: <50AB45EA.2050507@monom.org> References: <1353400211-5182-1-git-send-email-tj@kernel.org> <1353400211-5182-8-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Cc: nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, tgraf-G/eBtMaohhA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org To: Tejun Heo Return-path: In-Reply-To: <1353400211-5182-8-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: netdev.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