[bpf-next,v7,0/4] bpf: misc performance improvements for cgroup hooks

Message

Stanislav Fomichev Jan. 12, 2021, 10:38 p.m. UTC

First patch adds custom getsockopt for TCP_ZEROCOPY_RECEIVE
to remove kmalloc and lock_sock overhead from the dat path.

Second patch removes kzalloc/kfree from getsockopt for the common cases.

Third patch switches cgroup_bpf_enabled to be per-attach to
to add only overhead for the cgroup attach types used on the system.

No visible user-side changes.

v7:
- add comment about buffer contents for retval != 0 (Martin KaFai Lau)
- export tcp.h into tools/include/uapi (Martin KaFai Lau)
- note that v7 depends on the commit 4be34f3d0731 ("bpf: Don't leak
  memory in bpf getsockopt when optlen == 0") from bpf tree

v6:
- avoid indirect cost for new bpf_bypass_getsockopt (Eric Dumazet)

v5:
- reorder patches to reduce the churn (Martin KaFai Lau)

v4:
- update performance numbers
- bypass_bpf_getsockopt (Martin KaFai Lau)

v3:
- remove extra newline, add comment about sizeof tcp_zerocopy_receive
  (Martin KaFai Lau)
- add another patch to remove lock_sock overhead from
  TCP_ZEROCOPY_RECEIVE; technically, this makes patch #1 obsolete,
  but I'd still prefer to keep it to help with other socket
  options

v2:
- perf numbers for getsockopt kmalloc reduction (Song Liu)
- (sk) in BPF_CGROUP_PRE_CONNECT_ENABLED (Song Liu)
- 128 -> 64 buffer size, BUILD_BUG_ON (Martin KaFai Lau)

Stanislav Fomichev (4):
  bpf: remove extra lock_sock for TCP_ZEROCOPY_RECEIVE
  tools, bpf: add tcp.h to tools/uapi
  bpf: try to avoid kzalloc in cgroup/{s,g}etsockopt
  bpf: split cgroup_bpf_enabled per attach type

 include/linux/bpf-cgroup.h                    |  63 ++--
 include/linux/filter.h                        |   5 +
 include/linux/indirect_call_wrapper.h         |   6 +
 include/net/sock.h                            |   2 +
 include/net/tcp.h                             |   1 +
 kernel/bpf/cgroup.c                           | 112 +++++-
 net/ipv4/af_inet.c                            |   9 +-
 net/ipv4/tcp.c                                |  14 +
 net/ipv4/tcp_ipv4.c                           |   1 +
 net/ipv4/udp.c                                |   7 +-
 net/ipv6/af_inet6.c                           |   9 +-
 net/ipv6/tcp_ipv6.c                           |   1 +
 net/ipv6/udp.c                                |   7 +-
 net/socket.c                                  |   3 +
 tools/include/uapi/linux/tcp.h                | 357 ++++++++++++++++++
 .../selftests/bpf/prog_tests/sockopt_sk.c     |  22 ++
 .../testing/selftests/bpf/progs/sockopt_sk.c  |  15 +
 17 files changed, 582 insertions(+), 52 deletions(-)
 create mode 100644 tools/include/uapi/linux/tcp.h