The xdp_redirect_cpu sample have some "builtin" monitoring of the
tracepoints for xdp_cpumap_*, but it is practical to have an external
tool that can monitor these transpoint as an easy way to troubleshoot
an application using XDP + cpumap.
Specifically I need such external tool when working on Suricata and
XDP cpumap redirect. Extend the xdp_monitor tool sample with
monitoring of these xdp_cpumap_* tracepoints. Model the output format
like xdp_redirect_cpu.
Given I needed to handle per CPU decoding for cpumap, this patch also
add per CPU info on the existing monitor events. This resembles part
of the builtin monitoring output from sample xdp_rxq_info. Thus, also
covering part of that sample in an external monitoring tool.
Performance wise, the cpumap tracepoints uses bulking, which cause
them to have very little overhead. Thus, they are enabled by default.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Other concurrent running programs, like perf or the XDP program what
needed to be monitored, might take up part of the max locked memory
limit. Thus, the xdp_monitor tool have to set the RLIMIT_MEMLOCK to
RLIM_INFINITY, as it cannot determine a more sane limit.
Using the man exit(3) specified EXIT_FAILURE return exit code, and
correct other users too.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also monitor the tracepoint xdp_exception. This tracepoint is usually
invoked by the drivers. Programs themselves can activate this by
returning XDP_ABORTED, which will drop the packet but also trigger the
tracepoint. This is useful for distinguishing intentional (XDP_DROP)
vs. ebpf-program error cases that cased a drop (XDP_ABORTED).
Drivers also use this tracepoint for reporting on XDP actions that are
unknown to the specific driver. This can help the user to detect if a
driver e.g. doesn't implement XDP_REDIRECT yet.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make local functions static to fix
HOSTCC samples/bpf/xdp_monitor_user.o
samples/bpf/xdp_monitor_user.c:64:7: warning: no previous prototype for ‘gettime’ [-Wmissing-prototypes]
__u64 gettime(void)
^~~~~~~
samples/bpf/xdp_monitor_user.c:209:6: warning: no previous prototype for ‘print_bpf_prog_info’ [-Wmissing-prototypes]
void print_bpf_prog_info(void)
^~~~~~~~~~~~~~~~~~~
Fixes: 3ffab54602 ("samples/bpf: xdp_monitor tool based on tracepoints")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This tool xdp_monitor demonstrate how to use the different xdp_redirect
tracepoints xdp_redirect{,_map}{,_err} from a BPF program.
The default mode is to only monitor the error counters, to avoid
affecting the per packet performance. Tracepoints comes with a base
overhead of 25 nanosec for an attached bpf_prog, and 48 nanosec for
using a full perf record (with non-matching filter). Thus, default
loading the --stats mode could affect the maximum performance.
This version of the tool is very simple and count all types of errors
as one. It will be natural to extend this later with the different
types of errors that can occur, which should help users quickly
identify common mistakes.
Because the TP_STRUCT was kept in sync all the tracepoints loads the
same BPF code. It would also be natural to extend the map version to
demonstrate how the map information could be used.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jesper Dangaard Brouer
Stephen Hemminger