I think that isaku is talking about a more intensive usage of defer_apply_on/off as it is done in the patch of gongysh [1].
Isaku, i don't see any reason why this could not be done in precess_network_ports, if needed. Moreover the patch from edouard [2] resolves multithreading issues while precessing defer_apply_off. [1]https://review.openstack.org/#/c/61341/ [2]https://review.openstack.org/#/c/63917/ On Mon, Jan 6, 2014 at 9:24 PM, Salvatore Orlando <sorla...@nicira.com> wrote: > This thread is starting to get a bit confusing, at least for people with a > single-pipeline brain like me! > > I am not entirely sure if I understand correctly Isaku's proposal concerning > deferring the application of flow changes. > I think it's worth discussing in a separate thread, and a supporting patch > will help as well; I think that in order to avoid unexpected behaviours, > vlan tagging on the port and flow setup should always be performed at the > same time; if we get a much better performance using a mechanism similar to > iptables' defer_apply, then we should it. > > Regarding rootwrap. This 6x slowdown, while proving that rootwrap imposes a > non-negligible overhead, it should not be used as a sort of proof that > rootwrap makes things 6 times worse! What I've been seeing on the gate and > in my tests are ALRM_CLOCK errors raised by ovs commands, so rootwrap has > little to do with it. > > Still, I think we can say that rootwrap adds about 50ms to each command, > becoming particularly penalising especially for 'fast' commands. > I think the best things to do, as Joe advices, a test with rootwrap disabled > on the gate - and I will take care of that. > > On the other hand, I would invite community members picking up some of the > bugs we've registered for 'less frequent' failures observed during parallel > testing; especially if you're coming to Montreal next week. > > Salvatore > > > > On 6 January 2014 20:31, Jay Pipes <jaypi...@gmail.com> wrote: >> >> On Mon, 2014-01-06 at 11:17 -0800, Joe Gordon wrote: >> > >> > >> > >> > On Mon, Jan 6, 2014 at 10:35 AM, Jay Pipes <jaypi...@gmail.com> wrote: >> > On Mon, 2014-01-06 at 09:56 -0800, Joe Gordon wrote: >> > >> > > What about it? Also those numbers are pretty old at this >> > point. I was >> > > thinking disable rootwrap and run full parallel tempest >> > against it. >> > >> > >> > I think that is a little overkill for what we're trying to do >> > here. We >> > are specifically talking about combining many utils.execute() >> > calls into >> > a single one. I think it's pretty obvious that the latter will >> > be better >> > performing than the first, unless you think that rootwrap has >> > no >> > performance overhead at all? >> > >> > >> > mocking out rootwrap with straight sudo, is a very quick way to >> > approximate the performance benefit of combining many utlils.execute() >> > calls together (at least rootwrap wise). Also it would tell us how >> > much of the problem is rootwrap induced and how much is other. >> >> Yes, I understand that, which is what the article I linked earlier >> showed? >> >> % time sudo ip link >/dev/null >> sudo ip link > /dev/null 0.00s user 0.00s system 43% cpu 0.009 total >> % sudo time quantum-rootwrap /etc/quantum/rootwrap.conf ip link >> > /dev/null >> quantum-rootwrap /etc/quantum/rootwrap.conf ip link > /dev/null 0.04s >> user 0.02s system 87% cpu 0.059 total >> >> A very tiny, non-scientific simple indication that rootwrap is around 6 >> times slower than a simple sudo call. >> >> Best, >> -jay >> >> >> _______________________________________________ >> OpenStack-dev mailing list >> OpenStack-dev@lists.openstack.org >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev