So I did an experiment where I added 500 and 1000 ports and then deleted 500 and 1000 ports with and without this patch on both machines with 8 GB and 62 GB memory. Weirdly enough, adding / deleting ports with the RCU patch turned out to actually be faster than without. My only explanation here is taking the global xlate lock is expensive and / or 500 ports wasn't enough to induce memory pressure.
Here are the numbers for the 500 port case on a 8 GB memory machine: WIth RCU patch: Adding ports: real 1m15.850s Deleting ports: real 1m21.830s Without RCU patch: Adding ports: real 1m28.357s Deleting ports: real 1m33.277s Ryan Wilson Member of Technical Staff wr...@vmware.com 3401 Hillview Avenue, Palo Alto, CA 650.427.1511 Office 916.588.7783 Mobile On May 19, 2014, at 8:56 AM, Ben Pfaff <b...@nicira.com> wrote: > On Fri, May 16, 2014 at 06:59:02AM -0700, Ryan Wilson wrote: >> Before, a global read-write lock protected the ofproto-dpif / >> ofproto-dpif-xlate >> interface. Handler and revalidator threads had to wait while configuration >> was >> being changed. This patch implements RCU locking which allows handlers and >> revalidators to operate while configuration is being updated. >> >> Signed-off-by: Ryan Wilson <wr...@nicira.com> >> Acked-by: Alex Wang <al...@nicira.com> > > One side effect of this change that I am a bit concerned about is > performance of configuration changes. In particular, it looks like > removing a port requires copying the entire configuration and that > removing N ports requires copying the entire configuration N times. Can > you try a few experiments with configurations that have many ports, > maybe 500 or 1000, and see how long it takes to remove several of them? > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://urldefense.proofpoint.com/v1/url?u=http://openvswitch.org/mailman/listinfo/dev&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=TfBS78Vw3dzttvXidhbffg%3D%3D%0A&m=Zs91K1%2FqNCTCBEK8%2FYn6ZxlWk8%2B9KnAmWsxIFslVMIM%3D%0A&s=d0a516ff3c7de6162c8224e60363e8159c1da0eabe5ede2e10d43b18858e965d
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