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.
v2:
* add a comment about second accept() in selftest (Yonghong Song)
* refer to tcp_bpf.readme in sample program (Yonghong Song)
Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Priyaranjan Jha <priyarjha@xxxxxxxxxx>
Cc: Yuchung Cheng <ycheng@xxxxxxxxxx>
Cc: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Acked-by: Yuchung Cheng <ycheng@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 | 68 ++++++
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 | 254 ++++++++++++++++++++
11 files changed, 574 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
