Re: [PATCH v1 0/4] Remove BPF event support

[Jiri Olsa]

On Thu, Aug 10, 2023 at 11:48:49AM -0700, Ian Rogers wrote:
> The patch series removes BPF event support as past commits have shown
> the support has bit rotten:
> https://lore.kernel.org/lkml/20230728001212.457900-1-irogers@xxxxxxxxxx/
> 
> Similar functionality is now available via the --filter option, that
> uses a BPF skeleton, and is therefore more compact and simpler to
> use. The simplicity coming from not having to build BPF object files.
> 
> A different use case for the events was for syscall augmentation in
> perf trace. So that this isn't broken, and to make its use
> significantly simpler, the support is migrated to use a BPF
> skeleton. This means perf trace is much more likely to augment
> syscalls for users.
> 
> Removal of BPF events was raised on LKML two weeks ago with the
> original authors cc-ed:
> https://lore.kernel.org/lkml/CAP-5=fXxGimJRXKf7bcaPqfjxxGcn1k3CspY_iSjQnpAKs3uFQ@xxxxxxxxxxxxxx/
> 
> BPF events are described publicly in very few places but one is:
> https://www.brendangregg.com/perf.html#eBPF
> "eBPF is currently a little restricted and difficult to use from
> perf. It's getting better all the time. A different and currently
> easier way to access eBPF is via the bcc Python interface, which is
> described on my eBPF Tools page. On this page, I'll discuss perf."
> 
> I don't think the "getting better all the time" is any longer true as
> BPF features are being added to perf primarily by using BPF
> skeletons. The given example is a filter and would be better supported
> via "perf record --filter".

agreed, I don't think it's being really used as well,
also caused problems with libbpf updates

> 
> Ian Rogers (4):
>   perf parse-events: Remove BPF event support
>   perf trace: Migrate BPF augmentation to use a skeleton
>   perf bpf examples: With no BPF events remove examples
>   perf trace: Tidy comments
> 
>  tools/perf/Documentation/perf-config.txt      |   33 -
>  tools/perf/Documentation/perf-record.txt      |   22 -
>  tools/perf/Makefile.config                    |   43 -
>  tools/perf/Makefile.perf                      |   19 +-
>  tools/perf/builtin-record.c                   |   45 -
>  tools/perf/builtin-trace.c                    |  310 +--
>  tools/perf/examples/bpf/5sec.c                |   53 -
>  tools/perf/examples/bpf/empty.c               |   12 -
>  tools/perf/examples/bpf/hello.c               |   27 -
>  tools/perf/examples/bpf/sys_enter_openat.c    |   33 -
>  tools/perf/perf.c                             |    2 -
>  tools/perf/tests/.gitignore                   |    5 -
>  tools/perf/tests/Build                        |   31 -
>  tools/perf/tests/bpf-script-example.c         |   60 -
>  tools/perf/tests/bpf-script-test-kbuild.c     |   21 -
>  tools/perf/tests/bpf-script-test-prologue.c   |   49 -
>  tools/perf/tests/bpf-script-test-relocation.c |   51 -
>  tools/perf/tests/bpf.c                        |  390 ----
>  tools/perf/tests/builtin-test.c               |    3 -
>  tools/perf/tests/clang.c                      |   32 -
>  tools/perf/tests/llvm.c                       |  219 --
>  tools/perf/tests/llvm.h                       |   31 -
>  tools/perf/tests/make                         |    2 -
>  tools/perf/tests/tests.h                      |    2 -
>  tools/perf/trace/beauty/beauty.h              |   15 +-
>  tools/perf/util/Build                         |    8 +-
>  tools/perf/util/bpf-loader.c                  | 2006 -----------------
>  tools/perf/util/bpf-loader.h                  |  216 --
>  .../bpf_skel/augmented_raw_syscalls.bpf.c}    |   35 +-
>  tools/perf/util/c++/Build                     |    5 -
>  tools/perf/util/c++/clang-c.h                 |   43 -
>  tools/perf/util/c++/clang-test.cpp            |   67 -
>  tools/perf/util/c++/clang.cpp                 |  225 --
>  tools/perf/util/c++/clang.h                   |   27 -
>  tools/perf/util/config.c                      |    4 -
>  tools/perf/util/llvm-utils.c                  |  612 -----
>  tools/perf/util/llvm-utils.h                  |   69 -
>  tools/perf/util/parse-events.c                |  268 ---
>  tools/perf/util/parse-events.h                |   15 -
>  tools/perf/util/parse-events.l                |   31 -
>  tools/perf/util/parse-events.y                |   44 +-
>  41 files changed, 133 insertions(+), 5052 deletions(-)

awesome :)) 

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka

>  delete mode 100644 tools/perf/examples/bpf/5sec.c
>  delete mode 100644 tools/perf/examples/bpf/empty.c
>  delete mode 100644 tools/perf/examples/bpf/hello.c
>  delete mode 100644 tools/perf/examples/bpf/sys_enter_openat.c
>  delete mode 100644 tools/perf/tests/.gitignore
>  delete mode 100644 tools/perf/tests/bpf-script-example.c
>  delete mode 100644 tools/perf/tests/bpf-script-test-kbuild.c
>  delete mode 100644 tools/perf/tests/bpf-script-test-prologue.c
>  delete mode 100644 tools/perf/tests/bpf-script-test-relocation.c
>  delete mode 100644 tools/perf/tests/bpf.c
>  delete mode 100644 tools/perf/tests/clang.c
>  delete mode 100644 tools/perf/tests/llvm.c
>  delete mode 100644 tools/perf/tests/llvm.h
>  delete mode 100644 tools/perf/util/bpf-loader.c
>  delete mode 100644 tools/perf/util/bpf-loader.h
>  rename tools/perf/{examples/bpf/augmented_raw_syscalls.c => util/bpf_skel/augmented_raw_syscalls.bpf.c} (93%)
>  delete mode 100644 tools/perf/util/c++/Build
>  delete mode 100644 tools/perf/util/c++/clang-c.h
>  delete mode 100644 tools/perf/util/c++/clang-test.cpp
>  delete mode 100644 tools/perf/util/c++/clang.cpp
>  delete mode 100644 tools/perf/util/c++/clang.h
>  delete mode 100644 tools/perf/util/llvm-utils.c
>  delete mode 100644 tools/perf/util/llvm-utils.h
> 
> -- 
> 2.41.0.640.ga95def55d0-goog
>