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. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
