[PATCH net-next 0/4][pull request] igb: Add support for AF_XDP zero-copy

Tony Nguyen
2024-08-08T18:36:03Z

Kurt Kanzenbach says:

Since Sriram's duties changed I am sending this instead. Additionally,
I've tested this on real hardware, Intel i210 [1].

Changes since iwl-next v4:

- Rebase to v6.10
- Fix issue reported by kernel test robot
- Provide napi_id for for xdp_rxq_info_reg() so that busy polling works
- Set olinfo_status in igb_xmit_zc() so that frames are transmitted

Link to v4: https://lore.kernel.org/intel-wired-lan/20230804084051.14194-1-sriram.yagnaraman@est.tech/

[1] - https://github.com/Linutronix/TSN-Testbench/tree/main/tests/busypolling_i210

Original cover letter:

The first couple of patches adds helper functions to prepare for AF_XDP
zero-copy support which comes in the last couple of patches, one each
for Rx and TX paths.

As mentioned in v1 patchset [0], I don't have access to an actual IGB
device to provide correct performance numbers. I have used Intel 82576EB
emulator in QEMU [1] to test the changes to IGB driver.

The tests use one isolated vCPU for RX/TX and one isolated vCPU for the
xdp-sock application [2]. Hope these measurements provide at the least
some indication on the increase in performance when using ZC, especially
in the TX path. It would be awesome if someone with a real IGB NIC can
test the patch.

AF_XDP performance using 64 byte packets in Kpps.
Benchmark: XDP-SKB XDP-DRV XDP-DRV(ZC)
rxdrop 220 235 350
txpush 1.000 1.000 410
l2fwd 1.000 1.000 200

AF_XDP performance using 1500 byte packets in Kpps.
Benchmark: XDP-SKB XDP-DRV XDP-DRV(ZC)
rxdrop 200 210 310
txpush 1.000 1.000 410
l2fwd 0.900 1.000 160

[0]: https://lore.kernel.org/intel-wired-lan/20230704095915.9750-1-sriram.yagnaraman@est.tech/
[1]: https://www.qemu.org/docs/master/system/devices/igb.html
[2]: https://github.com/xdp-project/bpf-examples/tree/master/AF_XDP-example
---
iwl-next: https://lore.kernel.org/intel-wired-lan/20240711-b4-igb_zero_copy-v5-0-f3f455113b11@linutronix.de/

The following are changes since commit 91d516d4de48532d967a77967834e00c8c53dfe6:
net: mvpp2: Increase size of queue_name buffer
and are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 1GbE

Sriram Yagnaraman (4):
igb: prepare for AF_XDP zero-copy support
igb: Introduce XSK data structures and helpers
igb: add AF_XDP zero-copy Rx support
igb: add AF_XDP zero-copy Tx support

drivers/net/ethernet/intel/igb/Makefile | 2 +-
drivers/net/ethernet/intel/igb/igb.h | 35 +-
drivers/net/ethernet/intel/igb/igb_main.c | 189 ++++++--
drivers/net/ethernet/intel/igb/igb_xsk.c | 522 ++++++++++++++++++++++
4 files changed, 700 insertions(+), 48 deletions(-)
create mode 100644 drivers/net/ethernet/intel/igb/igb_xsk.c

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2.42.0