From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: Re: [Patch net-next v2] pktgen: support net namespace Date: Tue, 29 Jan 2013 11:54:37 +0800 Message-ID: <1359431677.20729.18.camel@cr0> References: <1359424389-21919-1-git-send-email-amwang@redhat.com> <874ni0k965.fsf@xmission.com> <1359428563.20729.12.camel@cr0> <877gmwirx5.fsf@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, "David S. Miller" To: "Eric W. Biederman" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:29621 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753276Ab3A2Dyp (ORCPT ); Mon, 28 Jan 2013 22:54:45 -0500 In-Reply-To: <877gmwirx5.fsf@xmission.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2013-01-28 at 19:33 -0800, Eric W. Biederman wrote: > Cong Wang writes: > > > On Mon, 2013-01-28 at 18:36 -0800, Eric W. Biederman wrote: > >> Cong Wang writes: > >> > >> > From: Cong Wang > >> > > >> > v2: remove a useless check > >> > > >> > This patch add net namespace to pktgen, so that > >> > we can use pktgen in different namespaces. > >> > > >> > Cc: Eric W. Biederman > >> > Cc: David S. Miller > >> > Signed-off-by: Cong Wang > >> > > >> > --- > >> > net/core/pktgen.c | 123 +++++++++++++++++++++++++++++++++++------------------ > >> > 1 files changed, 81 insertions(+), 42 deletions(-) > >> > >> Skiming through this again I have spotted what looks like a pretty > >> major bug. You are limiting yourself to one network device per network > >> namespace when the actual limit is one network device per thread. > >> > >> I think you can just kill the dev member of pktgen_net and the two or > >> three lines of code that touch it. > > > > Good point! > > > > It is used by pktgen_device_event() to check if the device generates the > > event is the one in our namespace. > > Which of course is trivial with dev_net()...; > > > It is safe to continue the search even if it is not in our namespace, > > but it is not efficient. Probably we need to make pktgen_threads list > > per-namespace. > > Having looked at the code a bit more I think the solution really is to > make the proc files per network namespace as you are doing, but to leave > the threads per cpu. Then it is just a matter of adding for_each_net > loops in the in the paths that add and remove the proc files. Hmm? pktgen creates each thread/proc file for each cpu, since proc files are per-namespace, we will have nr_cpu*nr_ns such proc files and threads. It hard to improve this due to this kind of design. I already finished v3 patch which makes pktgen_threads list per-ns, so far it works well. I am still testing it.