[ovs-dev] [PATCHv6 2/3] ofproto-dpif-sflow: Add snaplen for sample action and sFlow.

Ben Pfaff blp at ovn.org
Fri Jun 10 03:16:05 UTC 2016


On Thu, Jun 09, 2016 at 06:06:47PM -0700, William Tu wrote:
> > I'm not sure why CHECK_TRUNC_USERSPACE exists, because I think that your
> > patch implements the new action in userspace.
> 
> When translating sflow header config, only if it runs kernel datapath,
> I will program truncate to sample's actions list, ex:
> "sample(trunc(64), userspace(...))". If it runs userspace datapath,
> then it falls back to original way "sample(userspace(...))" and let
> sflow code cut the packet to 'header' size.

Why are the two datapaths treated differently?  Software is easier to
test if all the cases are similar, when possible.



More information about the dev mailing list