From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: Re: [BUG] Bug in netprio_cgroup and netcls_cgroup ? Date: Mon, 21 Jan 2013 09:50:12 +0100 Message-ID: <50FD0144.1000401@monom.org> References: <50FCDB5C.4050608@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50FCDB5C.4050608-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Li Zefan Cc: John Fastabend , Neil Horman , Daniel Wagner , LKML , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Cgroups Hi Li, On 21.01.2013 07:08, Li Zefan wrote: > I'm not a network developer, so correct me if I'm wrong. > > Since commit 7955490f732c2b8 > ("net: netprio_cgroup: rework update socket logic"), sock->sk->sk_cgrp_prioidx > is set when the socket is created, and won't be updated unless the task is > moved to another cgroup. > > Now the problem is, a socket can be _shared_ by multiple processes (fork, SCM_RIGHT). > If we place those processes in different cgroups, and each cgroup has > different configs, but all of the processes will send data via this socket > with the same network priority. Wouldn't that be addressed by 48a87cc26c13b68f6cce4e9d769fcb17a6b3e4b8 net: netprio: fd passed in SCM_RIGHTS datagram not set correctly A socket fd passed in a SCM_RIGHTS datagram was not getting updated with the new tasks cgrp prioidx. This leaves IO on the socket tagged with the old tasks priority. To fix this add a check in the scm recvmsg path to update the sock cgrp prioidx with the new tasks value. As I read this this should work for net_prio. > Similar with cls cgroup. but not for cls_cgroup because I forgot to apply that fix as well. Just a sec, about to send a patch for this. Thanks for looking into this! cheers, daniel