Hi Konstantin, On 10/7/21 2:27 PM, Konstantin Ananyev wrote: > v5 changes: > - Fix spelling (Thomas/David) > - Rename internal helper functions (David) > - Reorder patches and update commit messages (Thomas) > - Update comments (Thomas) > - Changed layout in rte_eth_fp_ops, to group functions and > related data based on their functionality: > first 64B line for Rx, second one for Tx. > Didn't observe any real performance difference comparing to > original layout. Though decided to keep a new one, as it seems > a bit more plausible. > > v4 changes: > - Fix secondary process attach (Pavan) > - Fix build failure (Ferruh) > - Update lib/ethdev/verion.map (Ferruh) > Note that moving newly added symbols from EXPERIMENTAL to DPDK_22 > section makes checkpatch.sh to complain. > > v3 changes: > - Changes in public struct naming (Jerin/Haiyue) > - Split patches > - Update docs > - Shamelessly included Andrew's patch: > > https://patches.dpdk.org/project/dpdk/patch/20210928154856.1015020-1-andrew.rybche...@oktetlabs.ru/ > into these series. > I have to do similar thing here, so decided to avoid duplicated effort. > > The aim of these patch series is to make rte_ethdev core data structures > (rte_eth_dev, rte_eth_dev_data, rte_eth_rxtx_callback, etc.) internal to > DPDK and not visible to the user. > That should allow future possible changes to core ethdev related structures > to be transparent to the user and help to improve ABI/API stability. > Note that current ethdev API is preserved, but it is a formal ABI break. > > The work is based on previous discussions at: > https://www.mail-archive.com/dev@dpdk.org/msg211405.html > https://www.mail-archive.com/dev@dpdk.org/msg216685.html > and consists of the following main points: > 1. Copy public 'fast' function pointers (rx_pkt_burst(), etc.) and > related data pointer from rte_eth_dev into a separate flat array. > We keep it public to still be able to use inline functions for these > 'fast' calls (like rte_eth_rx_burst(), etc.) to avoid/minimize slowdown. > Note that apart from function pointers itself, each element of this > flat array also contains two opaque pointers for each ethdev: > 1) a pointer to an array of internal queue data pointers > 2) points to array of queue callback data pointers. > Note that exposing this extra information allows us to avoid extra > changes inside PMD level, plus should help to avoid possible > performance degradation. > 2. Change implementation of 'fast' inline ethdev functions > (rte_eth_rx_burst(), etc.) to use new public flat array. > While it is an ABI breakage, this change is intended to be transparent > for both users (no changes in user app is required) and PMD developers > (no changes in PMD is required). > One extra note - with new implementation RX/TX callback invocation > will cost one extra function call with this changes. That might cause > some slowdown for code-path with RX/TX callbacks heavily involved. > Hope such trade-off is acceptable for the community. > 3. Move rte_eth_dev, rte_eth_dev_data, rte_eth_rxtx_callback and related > things into internal header: <ethdev_driver.h>. > > That approach was selected to: > - Avoid(/minimize) possible performance losses. > - Minimize required changes inside PMDs. > > Performance testing results (ICX 2.0GHz, E810 (ice)): > - testpmd macswap fwd mode, plus > a) no RX/TX callbacks: > no actual slowdown observed > b) bpf-load rx 0 0 JM ./dpdk.org/examples/bpf/t3.o: > ~2% slowdown > - l3fwd: no actual slowdown observed > > Would like to thank everyone who already reviewed and tested previous > versions of these series. All other interested parties please don't be shy > and provide your feedback.
Many thanks for the very good patch series. I hope we'll make it to be included in 21.11. If you need any help with cosmetic fixes suggested by me on review, please, let me know. Andrew.
