On Thu, Oct 21, 2021, at 00:32, Mike Pattrick wrote: > Currently when a user creates an openflow group with with multiple > buckets without specifying a selection type, the efficient dp_hash is > only selected if the user is creating fewer than 64 buckets. But when > dp_hash is explicitly selected, up to 256 buckets are supported. > > While up to 64 buckets seems like a lot, certain OVN/Open Stack > workloads could result in the user creating more than 64 buckets. For > example, when using OVN to load balance. This patch increases the > default maximum from 64 to 256. > > This change to the default limit doesn't affect how many buckets are > actually created, that is specified by the user when the group is > created, just how traffic is distributed across buckets. > > Signed-off-by: Mike Pattrick <[email protected]>
Going back to the patch from Jan Scheurich introducing the 64 buckets limit, I do not find a justification for this value. I have not found a good explanation for the 256 limit either. Reading group_setup_dp_hash_table() it is not clear why it's in place. So with the caveat that the big picture is eluding me, this change seems ok. It seems reasonable to improve the group selection method to have a better chance to use the more efficient method, while respecting the limits imposed by the implementation. It would be better to get to the bottom of it but it's not justification enough to block this change. Tests are passing, in particular the ones regarding group selection. Acked-by: Gaetan Rivet <[email protected]> -- Gaetan Rivet _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
