On Wed, Sep 18, 2019 at 12:17:08PM -0400, Willem de Bruijn wrote: > On Wed, Sep 18, 2019 at 3:25 AM Steffen Klassert > <steffen.klass...@secunet.com> wrote: > > > > This patchset adds support to do GRO/GSO by chaining packets > > of the same flow at the SKB frag_list pointer. This avoids > > the overhead to merge payloads into one big packet, and > > on the other end, if GSO is needed it avoids the overhead > > of splitting the big packet back to the native form. > > > > Patch 1 Enables UDP GRO by default. > > > > Patch 2 adds a netdev feature flag to enable listifyed GRO, > > this implements one of the configuration options discussed > > at netconf 2019. > > > > Patch 3 adds a netdev software feature set that defaults to off > > and assigns the new listifyed GRO feature flag to it. > > > > Patch 4 adds the core infrastructure to do fraglist GRO/GSO. > > > > Patch 5 enables UDP to use fraglist GRO/GSO if configured and no > > GRO supported socket is found. > > Very nice feature, Steffen. Aside from questions around performance, > my only question is really how this relates to GSO_BY_FRAGS.
They do the exact same thing AFAICT: they GSO according to a pre-formatted list of fragments/packets, and not to a specific size (such as MSS). > > More specifically, whether we can remove that in favor of using your > new skb_segment_list. That would actually be a big first step in > simplifying skb_segment back to something manageable. The main issue (that I know) on obsoleting GSO_BY_FRAGS is that dealing with frags instead of frag_list was considered easier to be offloaded, if ever attempted. So this would be a step back on that aspect. Other than this, it should be doable.
