On Tue, Apr 24, 2012 at 5:03 PM, K. Macy <kmacy_at_freebsd.org> wrote: > On Tue, Apr 24, 2012 at 4:16 PM, Li, Qing <qing.li_at_bluecoat.com> wrote: >>> >> >From previous tests, the difference between flowtable and >>>routing table was small with a single process (about 5% or 50ns >>>in the total packet processing time, if i remember well), >>>but there was a large gain with multiple concurrent processes. >>> >> >> Yes, that sounds about right when we did the tests a long while ago. >> >>> >>> Removing flowtable increases the cost in ip_output() >>> (obviously) but also in ether_output() (because the >>> route does not have a lle entry so you need to call >>> arpresolve on each packet). >>> >> >> Yup. >> >>> >>> So in revising the route lookup i believe it would be good >>> if we could also get at once most of the info that >>> ether_output() is computing again and again. >>> >> >> Well, the routing table no longer maintains any lle info, so there >> isn't much to copy out the rtentry at the completion of route >> lookup. >> >> If I understood you correctly, you do believe there is a lot of value >> in Flowtable caching concept, but you are not suggesting we reverting >> back to having the routing table maintain L2 entries, are you ? >> > > > One could try a similar conversion of the L2 table to an rmlock > without copy while lock is held. Odd .. *with* copy while lock is held. -KipReceived on Tue Apr 24 2012 - 13:05:31 UTC
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