On 26/08/2023 4:19, David Wei wrote: > From: David Wei <davidhwei@xxxxxxxx> > > This patchset is a proposal that adds zero copy network RX to io_uring. > With it, userspace can register a region of host memory for receiving > data directly from a NIC using DMA, without needing a kernel to user > copy. > > Software support is added to the Broadcom BNXT driver. Hardware support > for receive flow steering and header splitting is required. > > On the userspace side, a sample server is added in this branch of > liburing: > https://github.com/spikeh/liburing/tree/zcrx2 > > Build liburing as normal, and run examples/zcrx. Then, set flow steering > rules using ethtool. A sample shell script is included in > examples/zcrx_flow.sh, but you need to change the source IP. Finally, > connect a client using e.g. netcat and send data. > > This patchset + userspace code was tested on an Intel Xeon Platinum > 8321HC CPU and Broadcom BCM57504 NIC. > > Early benchmarks using this prototype, with iperf3 as a load generator, > showed a ~50% reduction in overall system memory bandwidth as measured > using perf counters. Note that DDIO must be disabled on Intel systems. > > Mina et al. from Google and Kuba are collaborating on a similar proposal > to ZC from NIC to devmem. There are many shared functionality in netdev > that we can collaborate on e.g.: > * Page pool memory provider backend and resource registration > * Page pool refcounted iov/buf representation and lifecycle > * Setting receive flow steering > > As mentioned earlier, this is an early prototype. It is brittle, some > functionality is missing and there's little optimisation. We're looking > for feedback on the overall approach and points of collaboration in > netdev. > * No copy fallback, if payload ends up in linear part of skb then the > code will not work > * No way to pin an RX queue to a specific CPU > * Only one ifq, one pool region, on RX queue... > > This patchset is based on the work by Jonathan Lemon > <jonathan.lemon@xxxxxxxxx>: > https://lore.kernel.org/io-uring/20221108050521.3198458-1-jonathan.lemon@xxxxxxxxx/ Hello David, This work looks interesting, is there anywhere I can read about it some more? Maybe it was presented (and hopefully recorded) in a recent conference? Maybe something geared towards adding more drivers support? I took a brief look at the bnxt patch and saw you converted the page pool allocation to data pool allocation, I assume this is done for data pages only, right? Headers are still allocated on page pool pages? Thanks
