On Wed, Feb 08, 2017 at 08:39:13AM -0800, John Fastabend wrote: > [...] > > > However, I came up with a new idea for the future and I'd like to show > > where I'm going. The idea is that we don't use s/g buffers on RX, so we > > have a pointer per descriptor untapped. So we can allow users to stick > > their own pointer in there, if they promise not to use s/g on this vq. > > With a full extra pointer to play with, we can go wild. > > I looked at this quickly it seems like it would work and allow us to avoid > the reset. However, it seems like a lot of churn to avoid a single reset. > I don't see the reset itself as being that bad of an operation. I agree the > reset is not ideal though. > > Are there any other use cases for this other than XDP?
Well in fact this would allow reducing MERGEABLE_BUFFER_ALIGN to L1_CACHE_BYTES so we save space per packet for regular networking. The idea to use build_skb would also benefit accordingly. I guess ndo_set_rx_headroom could benefit if we were to implement that. > > > > Take a look but it doesn't even build yet. > > Need to roll it out to all devices etc. > > > > ---> > > > > [...]
