From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Denis V. Lunev" Subject: Re: [PATCH] [NETNS49] support for per/namespace routing cache cleanup Date: Thu, 18 Oct 2007 23:01:44 +0400 Message-ID: <4717AD98.5000102@gmail.com> References: <20071017111215.GA29653@iris.sw.ru> <4715F60F.6060304@fr.ibm.com> <4716055D.4010102@sw.ru> <471610E8.8020008@fr.ibm.com> <471617CA.9090901@sw.ru> <471624C0.9020108@fr.ibm.com> <47164CBD.3040107@gmail.com> <471708D8.3080808@bull.net> <471772EB.2060206@sw.ru> <471789FD.5020802@bull.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <471789FD.5020802-6ktuUTfB/bM@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: Benjamin Thery Cc: Linux Containers , "Denis V. Lunev" , ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org List-Id: containers.vger.kernel.org Benjamin Thery wrote: > Denis V. Lunev wrote: >> Benjamin Thery wrote: >>> Denis V. Lunev wrote: >>>> Daniel Lezcano wrote: >>>>> Oh, by the way, I forgot something important you spotted with the list >>>>> protected by the mutex. >>>>> >>>>> When looking at ipv6/fib_hash.c with Benjamin, we need to browse the >>>>> network namespaces list for the garbage collecting, but we are in an >>>>> interrupt handler, so I can not use rtnl_lock. >>>> where exactly.... >>> Actually, it is in net/ipv6/ip6_fib.c, in fib6_clean_all(). >>> >>> fib6_clean_all() is called by fib6_run_gc() handler of the >>> ip6_fib_timer. If we don't want to have one such timer per net >>> namespace, in fib6_clean_all() we have to go through all net to clean >>> their own >>> fib_table_hash (using for_each_net() protected by rtnl_lock). >> after careful thinking, one timer per/namespace looks better for me :) > > Why? :) This is - scalable: no long-long iteration over 1000 namespace - easy in respect to a patch I just sent. We should not allow to drop cache from all namespaces from one - and this approach was good for Alexey Kuznetsov. We have talked about this discussing OpenVZ implementation > Then you'll have to find a way pass the target net to fib6_run_gc() > (the timer handler). current->nsproxy->net_ns won't work :) > One timer for all looked simpler to me. > > Can there be an impact on performance if we have several GC timers > for the several netns running? the amount of job is not greater. Isn't it? Regards, Den