[PATCH bpf-next 0/8] bpf: TCP RTT sock_ops bpf callback

[Stanislav Fomichev <sdf@google.com>]

Congestion control team would like to have a periodic callback to
track some TCP statistics. Let's add a sock_ops callback that can be
selectively enabled on a socket by socket basis and is executed for
every RTT. BPF program frequency can be further controlled by calling
bpf_ktime_get_ns and bailing out early.

I run neper tcp_stream and tcp_rr tests with the sample program
from the last patch and didn't observe any noticeable performance
difference.

Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Priyaranjan Jha <priyarjha@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>

Stanislav Fomichev (8):
  bpf: add BPF_CGROUP_SOCK_OPS callback that is executed on every RTT
  bpf: split shared bpf_tcp_sock and bpf_sock_ops implementation
  bpf: add dsack_dups/delivered{,_ce} to bpf_tcp_sock
  bpf: add icsk_retransmits to bpf_tcp_sock
  bpf/tools: sync bpf.h
  selftests/bpf: test BPF_SOCK_OPS_RTT_CB
  samples/bpf: add sample program that periodically dumps TCP stats
  samples/bpf: fix tcp_bpf.readme detach command

 include/net/tcp.h                           |   8 +
 include/uapi/linux/bpf.h                    |  12 +-
 net/core/filter.c                           | 207 +++++++++++-----
 net/ipv4/tcp_input.c                        |   4 +
 samples/bpf/Makefile                        |   1 +
 samples/bpf/tcp_bpf.readme                  |   2 +-
 samples/bpf/tcp_dumpstats_kern.c            |  65 +++++
 tools/include/uapi/linux/bpf.h              |  12 +-
 tools/testing/selftests/bpf/Makefile        |   3 +-
 tools/testing/selftests/bpf/progs/tcp_rtt.c |  61 +++++
 tools/testing/selftests/bpf/test_tcp_rtt.c  | 253 ++++++++++++++++++++
 11 files changed, 570 insertions(+), 58 deletions(-)
 create mode 100644 samples/bpf/tcp_dumpstats_kern.c
 create mode 100644 tools/testing/selftests/bpf/progs/tcp_rtt.c
 create mode 100644 tools/testing/selftests/bpf/test_tcp_rtt.c

-- 
2.22.0.410.gd8fdbe21b5-goog