[Intel-wired-lan] [PATCH v2 0/5] Introducing ixgbe AF_XDP ZC support

[William Tu]

On Tue, Oct 2, 2018 at 1:01 AM Björn Töpel <bjorn.topel at gmail.com> wrote:
>
> From: Björn Töpel <bjorn.topel at intel.com>
>
> Jeff: Please remove the v1 patches from your dev-queue!
>
> This patch set introduces zero-copy AF_XDP support for Intel's ixgbe
> driver.
>
> The ixgbe zero-copy code is located in its own file ixgbe_xsk.[ch],
> analogous to the i40e ZC support. Again, as in i40e, code paths have
> been copied from the XDP path to the zero-copy path. Going forward we
> will try to generalize more code between the AF_XDP ZC drivers, and
> also reduce the heavy C&P.
>
> We have run some benchmarks on a dual socket system with two Broadwell
> E5 2660 @ 2.0 GHz with hyperthreading turned off. Each socket has 14
> cores which gives a total of 28, but only two cores are used in these
> experiments. One for TR/RX and one for the user space application. The
> memory is DDR4 @ 2133 MT/s (1067 MHz) and the size of each DIMM is
> 8192MB and with 8 of those DIMMs in the system we have 64 GB of total
> memory. The compiler used is GCC 7.3.0. The NIC is Intel
> 82599ES/X520-2 10Gbit/s using the ixgbe driver.
>
> Below are the results in Mpps of the 82599ES/X520-2 NIC benchmark runs
> for 64B and 1500B packets, generated by a commercial packet generator
> HW blasting packets at full 10Gbit/s line rate. The results are with
> retpoline and all other spectre and meltdown fixes.
>
> AF_XDP performance 64B packets:
> Benchmark   XDP_DRV with zerocopy
> rxdrop        14.7
> txpush        14.6
> l2fwd         11.1
>
> AF_XDP performance 1500B packets:
> Benchmark   XDP_DRV with zerocopy
> rxdrop        0.8
> l2fwd         0.8
>
> XDP performance on our system as a base line.
>
> 64B packets:
> XDP stats       CPU     Mpps       issue-pps
> XDP-RX CPU      16      14.7       0
>
> 1500B packets:
> XDP stats       CPU     Mpps       issue-pps
> XDP-RX CPU      16      0.8        0
>
> The structure of the patch set is as follows:
>
> Patch 1: Introduce Rx/Tx ring enable/disable functionality
> Patch 2: Preparatory patche to ixgbe driver code for RX
> Patch 3: ixgbe zero-copy support for RX
> Patch 4: Preparatory patch to ixgbe driver code for TX
> Patch 5: ixgbe zero-copy support for TX
>
> Changes since v1:
>
> * Removed redundant AF_XDP precondition checks, pointed out by
>   Jakub. Now, the preconditions are only checked at XDP enable time.
> * Fixed a crash in the egress path, due to incorrect usage of
>   ixgbe_ring queue_index member. In v2 a ring_idx back reference is
>   introduced, and used in favor of queue_index. William reported the
>   crash, and helped me smoke out the issue. Kudos!

Thanks! I tested this series and no more crash.
The number is pretty good (*without* spectre and meltdown fixes)
model name : Intel(R) Xeon(R) CPU E5-2440 v2 @ 1.90GHz, total 16 cores/

AF_XDP performance 64B packets:
Benchmark   XDP_DRV with zerocopy
rxdrop        20
txpush        18
l2fwd         20

Regards,
William