Re: [PATCH bpf-next v5 00/16] AF_XDP infrastructure improvements and mlx5e support

From: "Björn Töpel" <bjorn.topel@gmail.com>
To: Maxim Mikityanskiy <maximmi@mellanox.com>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"Magnus Karlsson" <magnus.karlsson@intel.com>,
	"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Saeed Mahameed" <saeedm@mellanox.com>,
	"Jonathan Lemon" <bsd@fb.com>,
	"Tariq Toukan" <tariqt@mellanox.com>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"Jakub Kicinski" <jakub.kicinski@netronome.com>,
	"Maciej Fijalkowski" <maciejromanfijalkowski@gmail.com>
Subject: Re: [PATCH bpf-next v5 00/16] AF_XDP infrastructure improvements and mlx5e support
Date: Thu, 20 Jun 2019 11:13:23 +0200	[thread overview]
Message-ID: <CAJ+HfNia-vUv7Eumfs8aMYGGkxPbbUQ++F+BQ=9C1NtP0Jt3hA@mail.gmail.com> (raw)
In-Reply-To: <20190618120024.16788-1-maximmi@mellanox.com>

On Tue, 18 Jun 2019 at 14:00, Maxim Mikityanskiy <maximmi@mellanox.com> wrote:
>
> This series contains improvements to the AF_XDP kernel infrastructure
> and AF_XDP support in mlx5e. The infrastructure improvements are
> required for mlx5e, but also some of them benefit to all drivers, and
> some can be useful for other drivers that want to implement AF_XDP.
>
> The performance testing was performed on a machine with the following
> configuration:
>
> - 24 cores of Intel Xeon E5-2620 v3 @ 2.40 GHz
> - Mellanox ConnectX-5 Ex with 100 Gbit/s link
>
> The results with retpoline disabled, single stream:
>
> txonly: 33.3 Mpps (21.5 Mpps with queue and app pinned to the same CPU)
> rxdrop: 12.2 Mpps
> l2fwd: 9.4 Mpps
>
> The results with retpoline enabled, single stream:
>
> txonly: 21.3 Mpps (14.1 Mpps with queue and app pinned to the same CPU)
> rxdrop: 9.9 Mpps
> l2fwd: 6.8 Mpps
>
> v2 changes:
>
> Added patches for mlx5e and addressed the comments for v1. Rebased for
> bpf-next.
>
> v3 changes:
>
> Rebased for the newer bpf-next, resolved conflicts in libbpf. Addressed
> Björn's comments for coding style. Fixed a bug in error handling flow in
> mlx5e_open_xsk.
>
> v4 changes:
>
> UAPI is not changed, XSK RX queues are exposed to the kernel. The lower
> half of the available amount of RX queues are regular queues, and the
> upper half are XSK RX queues. The patch "xsk: Extend channels to support
> combined XSK/non-XSK traffic" was dropped. The final patch was reworked
> accordingly.
>
> Added "net/mlx5e: Attach/detach XDP program safely", as the changes
> introduced in the XSK patch base on the stuff from this one.
>
> Added "libbpf: Support drivers with non-combined channels", which aligns
> the condition in libbpf with the condition in the kernel.
>
> Rebased over the newer bpf-next.
>
> v5 changes:
>
> In v4, ethtool reports the number of channels as 'combined' and the
> number of XSK RX queues as 'rx' for mlx5e. It was changed, so that 'rx'
> is 0, and 'combined' reports the double amount of channels if there is
> an active UMEM - to make libbpf happy.
>
> The patch for libbpf was dropped. Although it's still useful and fixes
> things, it raises some disagreement, so I'm dropping it - it's no longer
> useful for mlx5e anymore after the change above.
>

Just a heads-up: There are some checkpatch warnings (>80 chars/line)
for the mlnx5 driver parts, and the series didn't apply cleanly on
bpf-next for me.

I haven't been able to test the mlnx5 parts.

Parts of the series are unrelated/orthogonal, and could be submitted
as separate series, e.g. patches {1,7} and patches {3,4}. No blockers
for me, though.

Thanks for the hard work!

For the series:
Acked-by: Björn Töpel <bjorn.topel@intel.com>