On Sun, Aug 18, 2013 at 02:56:55PM +1000, Simon Horman wrote: > On Thu, Aug 08, 2013 at 02:37:48PM -0700, Ben Pfaff wrote: > > On Thu, Aug 08, 2013 at 02:32:08PM -0700, Ethan Jackson wrote: > > > > Simon presented numbers that showed it to be a valuable optimization > > > > in some cases, otherwise I'd just say get rid of it. > > > > > > If that's the only reason we have it, I vote we ditch it. It's a new > > > world with multithreading, I'd like to have a clean slate in the > > > direction of thread safety and add optimizations back if they help in > > > this new paradigm > > > > That's the only reason we have it. If you want to ditch it be my > > guest. > > I accept that multi-threaded ovs-vswtichd is a whole new world > and that dropping optimisations that previously made sense is logical. > And I guess that the best thing is for the situation that lead to > this optimisation to be re-profiled once the multi-threading work is more > complete. > > For reference, my recollection is that this optimisation came > about because it was observed that inserting 100k non-expirable flows > would result in ovs-vswtichd consuming about 100% (of one) CPU running > through the list of flows to see if any of them were ready to be expired > although none of them ever would be. With the optimisation in place > CPU utilisation was reduced to roughly 0% as the list that was traversed > became empty and the system was otherwise idle.
I think it's perfectly reasonable to reintroduce the optimization. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
