From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: Re: net namespace plans for 2.6.25 (was Re: Pid namespaces problems) Date: Thu, 08 Nov 2007 16:58:13 +0300 Message-ID: <473315F5.20608@openvz.org> References: <472AE42F.5000602@openvz.org> <47301A14.9040304@openvz.org> <4731772D.3060806@fr.ibm.com> <47317EA7.6030500@free.fr> <4731E3DE.6000501@openvz.org> <4731F4BC.4000203@fr.ibm.com> <4732EA8E.7080400@sw.ru> <47330F1F.4080806@fr.ibm.com> <47331122.3000304@openvz.org> <47331241.2090501@fr.ibm.com> <473312FD.5030609@fr.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <473312FD.5030609-NmTC/0ZBporQT0dZR+AlfA@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 To: Daniel Lezcano Cc: Cedric Le Goater , "Eric W. Biederman" , "Denis V. Lunev" , Linux Containers , "Denis V. Lunev" , Benjamin Thery List-Id: containers.vger.kernel.org Daniel Lezcano wrote: > Denis V. Lunev wrote: > > Daniel Lezcano wrote: > >> Denis V. Lunev wrote: > >>> Daniel Lezcano wrote: > >>> > >>>> * the first one is the locking of the network namespace list by > >>>> rtnl_lock, so from the timer callback we can not browse the network > >>>> namespace list to check the age of the routes. It is a problem I would > >>>> like to talk with Denis if he has time > >>> From my point of view, the situation is clear. The timer should be > >>> per/namespace. The situation is completely different as one in IPv4. > >> We thought to make a timer per namespace for ipv6, but we are a little > >> afraid for the performances when there will be a lot of containers. > >> Anyway, we can do a timer per namespace and optimize that later. I will > >> cook a new patch to take into account that for the next week. > > > > IMHO not a problem. tcp_write_timer is per/socket timer. If this works > > efficiently, per/namespace one will work also. > > That's right, this is a good argument. By the way, the amount of work to > be done in the tcp_write_timer is perhaps smaller than the one done in > the ipv6 routing age check, no ? Anyway, I'm not against a timer per > namespace in this case, I already did a try before rolling back to a > for_each_net in the gc timer, that changes a little the API, but nothing We can easily make the netns list rcu protected to address this issue. If you're interested, I can prepare a patch tomorrow. > we can handle easily. > >