I feel this is as far as I can take the tracepoint infrastructure to
assist XDP monitoring.
Tracepoints comes with a base overhead of 25 nanosec for an attached
bpf_prog, and 48 nanosec for using a full perf record. This is
problematic for the XDP use-case, but it is very convenient to use the
existing perf infrastructure.
>From a performance perspective, the real solution would be to attach
another bpf_prog (that understand xdp_buff), but I'm not sure we want
to introduce yet another bpf attach API for this.
One thing left is to standardize the possible err return codes, to a
limited set, to allow easier (and faster) mapping into a bpf map.
---
Jesper Dangaard Brouer (7):
xdp: remove redundant argument to trace_xdp_redirect
xdp: tracepoint xdp_redirect also need a map argument
xdp: make xdp tracepoints report bpf prog id instead of prog_tag
xdp: separate xdp_redirect tracepoint in error case
xdp: separate xdp_redirect tracepoint in map case
samples/bpf: xdp_redirect load XDP dummy prog on TX device
samples/bpf: xdp_monitor tool based on tracepoints
include/trace/events/xdp.h | 100 ++++++++++--
net/core/filter.c | 37 +++-
samples/bpf/Makefile | 4
samples/bpf/xdp_monitor_kern.c | 88 ++++++++++
samples/bpf/xdp_monitor_user.c | 295 +++++++++++++++++++++++++++++++++++
samples/bpf/xdp_redirect_kern.c | 11 +
samples/bpf/xdp_redirect_map_kern.c | 11 +
samples/bpf/xdp_redirect_map_user.c | 22 ++-
samples/bpf/xdp_redirect_user.c | 21 ++
9 files changed, 543 insertions(+), 46 deletions(-)
create mode 100644 samples/bpf/xdp_monitor_kern.c
create mode 100644 samples/bpf/xdp_monitor_user.c
--
