On Mon, Jul 1, 2019 at 1:48 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Priyaranjan Jha <priyarjha@xxxxxxxxxx>
> Cc: Yuchung Cheng <ycheng@xxxxxxxxxx>
Acked-by: Yuchung Cheng <ycheng@xxxxxxxxxx>
Thanks!
> Cc: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
>
> 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
