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* [PATCH bpf-next v3 0/2] Refactor perf_event sample user program with libbpf bpf_link
@ 2020-03-13 11:52 Daniel T. Lee
  2020-03-13 11:52 ` [PATCH bpf-next v3 1/2] samples: bpf: move read_trace_pipe to trace_helpers Daniel T. Lee
  2020-03-13 11:52 ` [PATCH bpf-next v3 2/2] samples: bpf: refactor perf_event user program with libbpf bpf_link Daniel T. Lee
  0 siblings, 2 replies; 6+ messages in thread
From: Daniel T. Lee @ 2020-03-13 11:52 UTC (permalink / raw)
  To: Daniel Borkmann, Alexei Starovoitov
  Cc: John Fastabend, Andrii Nakryiko, netdev, bpf

Currently, some samples are using ioctl for enabling perf_event and
attaching BPF programs to this event. However, the bpf_program__attach
of libbpf(using bpf_link) is much more intuitive than the previous
method using ioctl.

bpf_program__attach_perf_event manages the enable of perf_event and
attach of BPF programs to it, so there's no neeed to do this
directly with ioctl.

In addition, bpf_link provides consistency in the use of API because it
allows disable (detach, destroy) for multiple events to be treated as
one bpf_link__destroy.

To refactor samples with using this libbpf API, the bpf_load in the
samples were removed and migrated to libbbpf. Because read_trace_pipe
is used in bpf_load, multiple samples cannot be migrated to libbpf,
this function was moved to trace_helpers.

Changes in v2:
 - check memory allocation is successful
 - clean up allocated memory on error

Changes in v3:
 - Improve pointer error check (IS_ERR())
 - change to calloc for easier destroy of bpf_link
 - remove perf_event fd list since bpf_link handles fd
 - use newer bpf_object__{open/load} API instead of bpf_prog_load
 - perf_event for _SC_NPROCESSORS_ONLN instead of _SC_NPROCESSORS_CONF
 - sample specific chagnes...

Daniel T. Lee (2):
  samples: bpf: move read_trace_pipe to trace_helpers
  samples: bpf: refactor perf_event user program with libbpf bpf_link

 samples/bpf/Makefile                        |   8 +-
 samples/bpf/bpf_load.c                      |  20 ----
 samples/bpf/bpf_load.h                      |   1 -
 samples/bpf/sampleip_user.c                 | 100 +++++++++++++-------
 samples/bpf/trace_event_user.c              |  89 ++++++++++++-----
 samples/bpf/tracex1_user.c                  |   1 +
 samples/bpf/tracex5_user.c                  |   1 +
 tools/testing/selftests/bpf/trace_helpers.c |  23 +++++
 tools/testing/selftests/bpf/trace_helpers.h |   1 +
 9 files changed, 159 insertions(+), 85 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-03-14  1:48 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-13 11:52 [PATCH bpf-next v3 0/2] Refactor perf_event sample user program with libbpf bpf_link Daniel T. Lee
2020-03-13 11:52 ` [PATCH bpf-next v3 1/2] samples: bpf: move read_trace_pipe to trace_helpers Daniel T. Lee
2020-03-13 11:52 ` [PATCH bpf-next v3 2/2] samples: bpf: refactor perf_event user program with libbpf bpf_link Daniel T. Lee
2020-03-13 18:48   ` Andrii Nakryiko
2020-03-14  1:45     ` Daniel T. Lee
2020-03-14  1:48       ` Andrii Nakryiko

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