[Patch bpf-next v4 0/4] tcp_bpf: improve ingress redirection performance with message corking

[Cong Wang <xiyou.wangcong@gmail.com>]

This patchset improves skmsg ingress redirection performance by a)
sophisticated batching with kworker; b) skmsg allocation caching with
kmem cache.

As a result, our patches significantly outperforms the vanilla kernel
in terms of throughput for almost all packet sizes. The percentage
improvement in throughput ranges from 3.13% to 160.92%, with smaller
packets showing the highest improvements.

For latency, it induces slightly higher latency across most packet sizes
compared to the vanilla, which is also expected since this is a natural
side effect of batching.

Here are the detailed benchmarks:

+-------------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+
| Throughput  | 64     | 128    | 256    | 512    | 1k     | 4k     | 16k    | 32k    | 64k    | 128k   | 256k   |
+-------------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+
| Vanilla     | 0.17±0.02 | 0.36±0.01 | 0.72±0.02 | 1.37±0.05 | 2.60±0.12 | 8.24±0.44 | 22.38±2.02 | 25.49±1.28 | 43.07±1.36 | 66.87±4.14 | 73.70±7.15 |
| Patched     | 0.41±0.01 | 0.82±0.02 | 1.62±0.05 | 3.33±0.01 | 6.45±0.02 | 21.50±0.08 | 46.22±0.31 | 50.20±1.12 | 45.39±1.29 | 68.96±1.12 | 78.35±1.49 |
| Percentage  | 141.18%   | 127.78%   | 125.00%   | 143.07%   | 148.08%   | 160.92%   | 106.52%    | 97.00%     | 5.38%      | 3.13%      | 6.32%      |
+-------------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+--------+

+-------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+
| Latency     | 64        | 128       | 256       | 512       | 1k        | 4k        | 16k       | 32k       | 63k       |
+-------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+
| Vanilla     | 5.80±4.02 | 5.83±3.61 | 5.86±4.10 | 5.91±4.19 | 5.98±4.14 | 6.61±4.47 | 8.60±2.59 | 10.96±5.50| 15.02±6.78|
| Patched     | 6.18±3.03 | 6.23±4.38 | 6.25±4.44 | 6.13±4.35 | 6.32±4.23 | 6.94±4.61 | 8.90±5.49 | 11.12±6.10| 14.88±6.55|
| Percentage  | 6.55%     | 6.87%     | 6.66%     | 3.72%     | 5.68%     | 4.99%     | 3.49%     | 1.46%     |-0.93%     |
+-------------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+

---
v4: pass false instead of 'redir_ingress' to tcp_bpf_sendmsg_redir()

v3: no change, just rebase

v2: improved commit message of patch 3/4
    changed to 'u8' for bitfields, as suggested by Jakub

Cong Wang (2):
  skmsg: rename sk_msg_alloc() to sk_msg_expand()
  skmsg: save some space in struct sk_psock

Zijian Zhang (2):
  skmsg: implement slab allocator cache for sk_msg
  tcp_bpf: improve ingress redirection performance with message corking

 include/linux/skmsg.h |  48 +++++++---
 net/core/skmsg.c      | 173 ++++++++++++++++++++++++++++++++---
 net/ipv4/tcp_bpf.c    | 204 +++++++++++++++++++++++++++++++++++++++---
 net/tls/tls_sw.c      |   6 +-
 net/xfrm/espintcp.c   |   2 +-
 5 files changed, 394 insertions(+), 39 deletions(-)

-- 
2.34.1