Commit Graph

10 Commits

Author SHA1 Message Date
Daniel T. Lee 321f632450 samples: bpf: Refactor XDP kern program maps with BTF-defined map
Most of the samples were converted to use the new BTF-defined MAP as
they moved to libbpf, but some of the samples were missing.

Instead of using the previous BPF MAP definition, this commit refactors
xdp_monitor and xdp_sample_pkts_kern MAP definition with the new
BTF-defined MAP format.

Also, this commit removes the max_entries attribute at PERF_EVENT_ARRAY
map type. The libbpf's bpf_object__create_map() will automatically
set max_entries to the maximum configured number of CPUs on the host.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201010181734.1109-4-danieltimlee@gmail.com
2020-10-11 12:14:36 -07:00
Toke Høiland-Jørgensen 7cf245a37e samples/bpf: Use consistent include paths for libbpf
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 16:37:45 -08:00
Jesper Dangaard Brouer 58aa94f922 devmap: Adjust tracepoint for map-less queue flush
Now that we don't have a reference to a devmap when flushing the device
bulk queue, let's change the the devmap_xmit tracepoint to remote the
map_id and map_index fields entirely. Rearrange the fields so 'drops' and
'sent' stay in the same position in the tracepoint struct, to make it
possible for the xdp_monitor utility to read both the old and the new
format.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157918768613.1458396.9165902403373826572.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Jesper Dangaard Brouer a570e48fee samples/bpf: xdp_monitor use err code from tracepoint xdp:xdp_devmap_xmit
Update xdp_monitor to use the recently added err code introduced
in tracepoint xdp:xdp_devmap_xmit, to show if the drop count is
caused by some driver general delivery problem.  Other kind of drops
will likely just be more normal TX space issues.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-24 18:36:15 -07:00
Jesper Dangaard Brouer 9940fbf633 samples/bpf: xdp_monitor use tracepoint xdp:xdp_devmap_xmit
The xdp_monitor sample/tool is updated to use the new tracepoint
xdp:xdp_devmap_xmit the previous patch just introduced.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-24 18:36:15 -07:00
Jesper Dangaard Brouer 417f1d9f21 samples/bpf: xdp_monitor include cpumap tracepoints in monitoring
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>
2018-01-20 02:10:55 +01:00
Luis de Bethencourt 4c38f74c91 samples/bpf: Fix trailing semicolon
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-17 00:23:58 +01:00
Jesper Dangaard Brouer 280b058d48 samples/bpf: xdp_monitor also record xdp_exception tracepoint
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>
2017-10-06 10:04:35 -07:00
Jesper Dangaard Brouer f4ce0a0116 samples/bpf: xdp_monitor first 8 bytes are not accessible by bpf
The first 8 bytes of the tracepoint context struct are not accessible
by the bpf code.  This is a choice that dates back to the original
inclusion of this code.

See explaination in:
 commit 98b5c2c65c ("perf, bpf: allow bpf programs attach to tracepoints")

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>
2017-10-06 10:04:35 -07:00
Jesper Dangaard Brouer 3ffab54602 samples/bpf: xdp_monitor tool based on tracepoints
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>
2017-08-29 10:51:29 -07:00