On Wed, 05 Jun 2019 12:14:50 -0700 (PDT) David Miller <da...@davemloft.net> wrote:
> From: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > Date: Wed, 5 Jun 2019 16:20:02 +0300 > > > This patchset adds XDP support for TI cpsw driver and base it on > > page_pool allocator. It was verified on af_xdp socket drop, > > af_xdp l2f, ebpf XDP_DROP, XDP_REDIRECT, XDP_PASS, XDP_TX. > > Jesper et al., please give this a good once over. The issue with merging this, is that I recently discovered two bug with page_pool API, when using DMA-mappings, which result in missing DMA-unmap's. These bugs are not "exposed" yet, but will get exposed now with this drivers. The two bugs are: #1: in-flight packet-pages can still be on remote drivers TX queue, while XDP RX driver manage to unregister the page_pool (waiting 1 RCU period is not enough). #2: this patchset also introduce page_pool_unmap_page(), which is called before an XDP frame travel into networks stack (as no callback exist, yet). But the CPUMAP redirect *also* needs to call this, else we "leak"/miss DMA-unmap. I do have a working prototype, that fixes these two bugs. I guess, I'm under pressure to send this to the list soon... -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
