> >Bhanuprakash Bodireddy <bhanuprakash.bodire...@intel.com> writes: > >> pkt_metadata_prefetch_init() is used to prefetch the packet metadata >> before initializing the metadata in pkt_metadata_init(). This is done >> for every packet in userspace datapath and is performance critical. >> >> Commit 99fc16c0 prefetches only cachline0 and cacheline2 as the >> metadata part of respective cachelines will be initialized by >pkt_metadata_init(). >> >> However in VXLAN case when popping the vxlan header, >> netdev_vxlan_pop_header() invokes pkt_metadata_init_tnl() which zeroes >> out metadata part of >> cacheline1 that wasn't prefetched earlier and causes performance >> degradation. >> >> By prefetching cacheline1, 9% performance improvement is observed. > >Do we see a degredation in the non-vxlan case? If not, then I don't see any >reason not to apply this patch.
This patch doesn't impact the performance of non-vxlan cases and only have a positive impact in vxlan case. - Bhanuprakash. _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
