> Subject: RE: [PATCH net-next 1/4] dpaa2-eth: Use a single page per Rx buffer > > > Subject: Re: [PATCH net-next 1/4] dpaa2-eth: Use a single page per Rx > > buffer > > > > > > On Wed, 6 Feb 2019 15:36:33 +0000 Ioana Ciocoi Radulescu > > <ruxandra.radule...@nxp.com> wrote: > > > > > > From: Ilias Apalodimas <ilias.apalodi...@linaro.org> > > > > > > > > Can you share any results on XDP (XDP_DROP is usually useful for > > > > the hardware capabilities). > > > > > > XDP numbers are pretty much the same as before this patch: > > > > > > On a LS2088A with A72 cores @2GHz (numbers in Mpps): > > > 1core 8cores > > > ------------------------------------------------------------------------- > > > XDP_DROP (no touching data) 5.37 29.6 (linerate) > > > XDP_DROP (xdp1 sample) 3.14 24.22 > > > > It is interesting/problematic to see that the cost of touching the > > data is so high 5.37Mpps -> 3.14Mpps. The Intel CPUs have solved this > > in hardware with DDIO, which delivers frame in L3-cache. I have some > > ideas on how to improve this on ARM (or CPUs without DDIO). I've > > previous implemented this as RFC on mlx4 tested on a CPU without DDIO, > > with great success 10mpps -> 20Mpps (but it was shutdown, as newer > > Intel HW solved the issue). The basic idea is to have an array of > > frames, that you start an L2/L3-prefetch on, before going "back" and > > process them for XDP or netstack. (p.s. this is the same DPDK does) > > Thanks for the hint. We are currently investigating what our options are. > We'll come back with a more detailed answer once we figure out. >
Hi, We have enabled cache stashing of frame data in our solution and sent the patches upstream: https://lkml.org/lkml/2019/2/23/41. Some results with the patches applied on top of the net-next tree are below. LS2088A with A72 cores @2GHz (numbers in Mpps): 1core 8cores -------------------------------------------------------------------------------------------------------- XDP_DROP (no touching data) 5.37 29.6 (linerate) XDP_DROP (xdp1 sample, no stashing) 3.28 24.2 XDP_DROP (xdp1 sample, stashing) 4.64 26.85 Thanks a lot for your hint. Ioana C
