| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <0cd7fa8a-6fe6-9945-4656-b4bd941b3d3c@redhat.com>
Date: Wed, 9 Aug 2023 22:09:10 +0200
From: Jesper Dangaard Brouer <jbrouer@...hat.com>
To: Stanislav Fomichev <sdf@...gle.com>, bpf@...r.kernel.org
Cc: brouer@...hat.com, ast@...nel.org, daniel@...earbox.net,
andrii@...nel.org, martin.lau@...ux.dev, song@...nel.org, yhs@...com,
john.fastabend@...il.com, kpsingh@...nel.org, haoluo@...gle.com,
jolsa@...nel.org, kuba@...nel.org, toke@...nel.org, willemb@...gle.com,
dsahern@...nel.org, magnus.karlsson@...el.com, bjorn@...nel.org,
maciej.fijalkowski@...el.com, hawk@...nel.org, netdev@...r.kernel.org,
xdp-hints@...-project.net, Saeed Mahameed <saeedm@...dia.com>
Subject: Re: [xdp-hints] [PATCH bpf-next 0/9] xsk: TX metadata
On 09/08/2023 18.54, Stanislav Fomichev wrote:
> This series implements initial TX metadata (offloads) for AF_XDP.
> See patch #2 for the main implementation and mlx5-one for the
> example on how to consume the metadata on the device side.
>
> Starting with two types of offloads:
> - request TX timestamp (and write it back into the metadata area)
> - request TX checksum offload
>
> Changes since last RFC:
> - add /* private: */ comments to headers (Simon)
> - handle metadata only in the first frag (Simon)
> - rename xdp_hw_metadata flags (Willem)
> - s/tmo_request_checksum/tmo_request_timestamp/ in xdp_metadata_ops
> comment (Willem)
> - Documentation/networking/xsk-tx-metadata.rst
>
> RFC v4: https://lore.kernel.org/bpf/20230724235957.1953861-1-sdf@google.com/
>
> Performance:
>
> I've implemented a small xskgen tool to try to saturate single tx queue:
> https://github.com/fomichev/xskgen/tree/master
>
> Here are the performance numbers with some analysis.
>
What is the clock freq GHz for the CPU used for this benchmark?
> 1. Baseline. Running with commit eb62e6aef940 ("Merge branch 'bpf:
> Support bpf_get_func_ip helper in uprobes'"), nothing from this series:
>
> - with 1400 bytes of payload: 98 gbps, 8 mpps
> ./xskgen -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.189130 sec, 98.357623 gbps 8.409509 mpps
>
> - with 200 bytes of payload: 49 gbps, 23 mpps
> ./xskgen -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000064 packets 20960134144 bits, took 0.422235 sec, 49.640921 gbps 23.683645 mpps
>
> 2. Adding single commit that supports reserving XDP_TX_METADATA_LEN
> changes nothing numbers-wise.
>
> - baseline for 1400
> ./xskgen -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.189247 sec, 98.347946 gbps 8.408682 mpps
>
> - baseline for 200
> ./xskgen -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 20960000000 bits, took 0.421248 sec, 49.756913 gbps 23.738985 mpps
>
> 3. Adding -M flag causes xskgen to reserve the metadata and fill it, but
> doesn't set XDP_TX_METADATA descriptor option.
>
> - new baseline for 1400 (with only filling the metadata)
> ./xskgen -M -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.188767 sec, 98.387657 gbps 8.412077 mpps
>
> - new baseline for 200 (with only filling the metadata)
> ./xskgen -M -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 20960000000 bits, took 0.410213 sec, 51.095407 gbps 24.377579 mpps
> (the numbers go sligtly up here, not really sure why, maybe some cache-related
> side-effects?
>
Notice this change/improvement (23.7 to 24.4 Mpps) is only 1 nanosec.
- (1/24.377579-1/23.738985)*10^3 = -1.103499 nanosec
This 1 nanosec could be noise in your testlab.
> 4. Next, I'm running the same test but with the commit that adds actual
> general infra to parse XDP_TX_METADATA (but no driver support).
> Essentially applying "xsk: add TX timestamp and TX checksum offload support"
> from this series. Numbers are the same.
>
> - fill metadata for 1400
> ./xskgen -M -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.188430 sec, 98.415557 gbps 8.414463 mpps
>
> - fill metadata for 200
> ./xskgen -M -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 20960000000 bits, took 0.411559 sec, 50.928299 gbps 24.297853 mpps
>
> - request metadata for 1400
> ./xskgen -m -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.188723 sec, 98.391299 gbps 8.412389 mpps
>
> - request metadata for 200
> ./xskgen -m -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000064 packets 20960134144 bits, took 0.411240 sec, 50.968131 gbps 24.316856 mpps
>
> 5. Now, for the most interesting part, I'm adding mlx5 driver support.
> The mpps for 200 bytes case goes down from 23 mpps to 19 mpps, but
> _only_ when I enable the metadata. This looks like a side effect
> of me pushing extra metadata pointer via mlx5e_xdpi_fifo_push.
> Hence, this part is wrapped into 'if (xp_tx_metadata_enabled)'
> to not affect the existing non-metadata use-cases. Since this is not
> regressing existing workloads, I'm not spending any time trying to
> optimize it more (and leaving it up to mlx owners to purse if
> they see any good way to do it).
>
> - same baseline
> ./xskgen -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.189434 sec, 98.332484 gbps 8.407360 mpps
>
> ./xskgen -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000128 packets 20960268288 bits, took 0.425254 sec, 49.288821 gbps 23.515659 mpps
>
> - fill metadata for 1400
> ./xskgen -M -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.189528 sec, 98.324714 gbps 8.406696 mpps
>
> - fill metadata for 200
> ./xskgen -M -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000128 packets 20960268288 bits, took 0.519085 sec, 40.379260 gbps 19.264914 mpps
>
This change from 23 mpps to 19 mpps is approx 10 nanosec
- (1/23.738985-1/19.264914)*10^3 = -9.78 nanosec
- (1/23.515659-1/19.264914)*10^3 = -9.38 nanosec
A 10 nanosec difference is more than noise.
> - request metadata for 1400
> ./xskgen -m -s 1400 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000000 packets 116960000000 bits, took 1.189329 sec, 98.341165 gbps 8.408102 mpps
>
> - request metadata for 200
> ./xskgen -m -s 200 -b eth3 10:70:fd:48:10:77 10:70:fd:48:10:87 fe80::1270:fdff:fe48:1077 fe80::1270:fdff:fe48:1087 1 1
> sent 10000128 packets 20960268288 bits, took 0.519929 sec, 40.313713 gbps 19.233642 mpps
>
> Cc: Saeed Mahameed <saeedm@...dia.com>
>
> Stanislav Fomichev (9):
> xsk: Support XDP_TX_METADATA_LEN
> xsk: add TX timestamp and TX checksum offload support
> tools: ynl: print xsk-features from the sample
> net/mlx5e: Implement AF_XDP TX timestamp and checksum offload
> selftests/xsk: Support XDP_TX_METADATA_LEN
> selftests/bpf: Add csum helpers
> selftests/bpf: Add TX side to xdp_metadata
> selftests/bpf: Add TX side to xdp_hw_metadata
> xsk: document XDP_TX_METADATA_LEN layout
>
> Documentation/netlink/specs/netdev.yaml | 20 ++
> Documentation/networking/index.rst | 1 +
> Documentation/networking/xsk-tx-metadata.rst | 75 +++++++
> drivers/net/ethernet/mellanox/mlx5/core/en.h | 4 +-
> .../net/ethernet/mellanox/mlx5/core/en/xdp.c | 72 ++++++-
> .../net/ethernet/mellanox/mlx5/core/en/xdp.h | 10 +-
> .../ethernet/mellanox/mlx5/core/en/xsk/tx.c | 11 +-
> .../net/ethernet/mellanox/mlx5/core/en_main.c | 1 +
> include/linux/netdevice.h | 27 +++
> include/linux/skbuff.h | 5 +-
> include/net/xdp_sock.h | 61 ++++++
> include/net/xdp_sock_drv.h | 13 ++
> include/net/xsk_buff_pool.h | 6 +
> include/uapi/linux/if_xdp.h | 36 ++++
> include/uapi/linux/netdev.h | 16 ++
> net/core/netdev-genl.c | 12 +-
> net/xdp/xsk.c | 61 ++++++
> net/xdp/xsk_buff_pool.c | 1 +
> net/xdp/xsk_queue.h | 19 +-
> tools/include/uapi/linux/if_xdp.h | 50 ++++-
> tools/include/uapi/linux/netdev.h | 15 ++
> tools/net/ynl/generated/netdev-user.c | 19 ++
> tools/net/ynl/generated/netdev-user.h | 3 +
> tools/net/ynl/samples/netdev.c | 6 +
> tools/testing/selftests/bpf/network_helpers.h | 43 ++++
> .../selftests/bpf/prog_tests/xdp_metadata.c | 31 ++-
> tools/testing/selftests/bpf/xdp_hw_metadata.c | 201 +++++++++++++++++-
> tools/testing/selftests/bpf/xsk.c | 17 ++
> tools/testing/selftests/bpf/xsk.h | 1 +
> 29 files changed, 793 insertions(+), 44 deletions(-)
> create mode 100644 Documentation/networking/xsk-tx-metadata.rst
>
Thanks for working on this :-)
--Jesper
Powered by blists - more mailing lists