Re: [RFC 00/79] perf tools: Initial libperf separation

From: Ian Rogers
Date: Mon Jul 22 2019 - 12:23:54 EST


This is really helpful and thank you for taking the initiative! I've
no real feedback other than to offer support.
We've been looking in this direction to avoid memory overhead in:
https://github.com/google/perf_data_converter
Some use cases:
1) streaming protobuf rather than perf.data files,
2) using libperf inside of a runtime with JIT for a symbolization
story that can reduce the storage/memory overhead of the current 'perf
record' and 'perf inject -j'. Something similar is done here:
https://github.com/jvm-profiling-tools/async-profiler/blob/936a9fea8dafc5d0674860d229a1b3d86d295e2f/src/perfEvents_linux.cpp
3) self profiling with dwarf based call graphs, to avoid stack samples
being visible outside of the process which could be a security
concern.

Most of our tooling is C++ rather than C, and we run into issues like
tools/include/linux/list.h using 'new' as a variable name. The
duplication of header files in tools/, the importance of -I precedence
and the use of -include have been other build system gotchas -
principally because there are so many files with exactly the same
name. I don't know if in the reorganization into a library this can be
simplified.

Thanks again,
Ian Rogers
Google

On Sun, Jul 21, 2019 at 4:25 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> hi,
> we have long term goal to separate some of the perf functionality
> into library. This patchset is initial effort on separating some
> of the interface.
>
> Currently only the basic counting interface is exported, it allows
> to:
> - create cpu/threads maps
> - create evlist/evsel objects
> - add evsel objects into evlist
> - open/close evlist/evsel objects
> - enable/disable events
> - read evsel counts
>
> The initial effort was to have total separation of the objects
> from perf code, but it showed not to be a good way. The amount
> of changed code was too big with high chance for regressions,
> mainly because of the code embedding one of the above objects
> statically.
>
> We took the other approach of sharing the objects/struct details
> within the perf and libperf code. This way we can keep perf
> functionality without any major changes and the libperf users
> are still separated from the object/struct details. We can move
> to total libperf's objects separation gradually in future.
>
> You can check current interface/functionality in examples under:
> tools/perf/lib/Documentation/tutorial
>
> or check tests in here:
> $ cd tools/perf/lib && make tests
> LINK test-cpumap-a
> LINK test-threadmap-a
> LINK test-evlist-a
> LINK test-evsel-a
> LINK test-cpumap-so
> LINK test-threadmap-so
> LINK test-evlist-so
> LINK test-evsel-so
> running static:
> - running test-cpumap.c...OK
> - running test-threadmap.c...OK
> - running test-evlist.c...OK
> - running test-evsel.c...OK
> running dynamic:
> - running test-cpumap.c...OK
> - running test-threadmap.c...OK
> - running test-evlist.c...OK
> - running test-evsel.c...OK
>
> The upcoming changes in the near future:
> - move parse_events interface in, so we have the event parsing
> interface in the library together with the all events from
> tools/perf/pmu-events/arch
> - add sampling interface with event mmap support and all the
> sampling events objects
> - add user mmap interface to read counters
> - more documentation and tutorial ;-)
> - move under tools/lib after the interface is more stable-ish
>
> Big kudos to BPF guys, because most of the infrastructure is
> 'borrowed' from libbpf library.. ;-)
>
> It's also available in here:
> git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> perf/lib
>
> I tested so far on x86, I still need to run it through s390/ppc/arm.
>
> throughts? thanks,
> jirka
>
>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
> Cc: Song Liu <songliubraving@xxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Stephane Eranian <eranian@xxxxxxxxxx>
> ---
> Jiri Olsa (79):
> perf tools: Move loaded out of struct perf_counts_values
> perf tools: Rename struct cpu_map to struct perf_cpu_map
> perf tools: Rename struct thread_map to struct perf_thread_map
> perf tools: Rename struct perf_evsel to struct evsel
> perf tools: Rename struct perf_evlist to struct evlist
> perf tools: Rename perf_evsel__init to evsel__init
> perf tools: Rename perf_evlist__init to evlist__init
> perf tools: Rename perf_evlist__new to evlist__new
> perf tools: Rename perf_evlist__delete to evlist__delete
> perf tools: Rename perf_evsel__delete to evsel__delete
> perf tools: Rename perf_evsel__new to evsel__new
> perf tools: Rename perf_evlist__add to evlist__add
> perf tools: Rename perf_evlist__remove to evlist__remove
> perf tools: Rename perf_evsel__open to evsel__open
> perf tools: Rename perf_evsel__enable to evsel__enable
> perf tools: Rename perf_evsel__disable to evsel__disable
> perf tools: Rename perf_evsel__apply_filter to evsel__apply_filter
> perf tools: Rename perf_evsel__cpus to evsel__cpus
> perf tools: Rename perf_evlist__open to evlist__open
> perf tools: Rename perf_evlist__close to evlist__close
> perf tools: Rename perf_evlist__enable to evlist__enable
> perf tools: Rename perf_evlist__disable to evlist__disable
> libperf: Make libperf.a part of the build
> libperf: Add build version support
> libperf: Add libperf in python.so compilation
> libperf: Add perf/core.h header
> libperf: Add debug output support
> libperf: Add perf_cpu_map struct
> libperf: Add perf_cpu_map__dummy_new function
> libperf: Add perf_cpu_map__get/perf_cpu_map__put
> libperf: Add perf_thread_map struct
> libperf: Add perf_thread_map__new_dummy function
> libperf: Add perf_thread_map__get/perf_thread_map__put
> libperf: Add perf_evlist and perf_evsel structs
> libperf: Include perf_evsel in evsel object
> libperf: Include perf_evlist in evlist object
> libperf: Add perf_evsel__init function
> libperf: Add perf_evlist__init function
> libperf: Add perf_evlist__add function
> libperf: Add perf_evlist__remove function
> libperf: Add nr_entries to perf_evlist
> libperf: Add attr to perf_evsel
> libperf: Add perf_cpu_map__new/perf_cpu_map__read functions
> libperf: Move zalloc.o into libperf
> libperf: Add perf_evlist__new function
> libperf: Add perf_evsel__new function
> libperf: Add perf_evlist__for_each_evsel macro
> libperf: Add perf_evlist__delete function
> libperf: Add perf_evsel__delete function
> libperf: Add cpus to struct perf_evsel
> libperf: Add own_cpus to struct perf_evsel
> libperf: Add threads to struct perf_evsel
> libperf: Add has_user_cpus to struct perf_evlist
> libperf: Add cpus to struct perf_evlist
> libperf: Add threads to struct perf_evlist
> libperf: Add perf_evlist__set_maps function
> libperf: Add xyarray object
> libperf: Add fd array to struct perf_evsel
> libperf: Add nr_members to struct perf_evsel
> libperf: Add readn/writen function
> libperf: Add perf_evsel__alloc_fd function
> libperf: Add perf_evsel__open function
> libperf: Add perf_evsel__close function
> libperf: Add perf_evsel__read function
> libperf: Add perf_evsel__enable/disable/apply_filter functions
> libperf: Add perf_cpu_map__for_each_cpu macro
> libperf: Add perf_evsel__cpus/threads functions
> libperf: Add perf_evlist__open/close functions
> libperf: Add perf_evlist__enable/disable functions
> libperf: Add perf_evsel__attr functions
> libperf: Add install targets
> libperf: Add tests support
> libperf: Add perf_cpu_map test
> libperf: Add perf_thread_map test
> libperf: Add perf_evlist test
> libperf: Add perf_evsel tests
> libperf: Add perf_evlist__enable/disable test
> libperf: Add perf_evsel__enable/disable test
> libperf: Initial documentation
>
> tools/perf/Makefile.config | 1 +
> tools/perf/Makefile.perf | 31 +-
> tools/perf/arch/arm/util/auxtrace.c | 4 +-
> tools/perf/arch/arm/util/cs-etm.c | 26 +-
> tools/perf/arch/arm64/util/arm-spe.c | 6 +-
> tools/perf/arch/powerpc/util/kvm-stat.c | 12 +-
> tools/perf/arch/s390/util/auxtrace.c | 8 +-
> tools/perf/arch/s390/util/kvm-stat.c | 8 +-
> tools/perf/arch/x86/tests/intel-cqm.c | 8 +-
> tools/perf/arch/x86/tests/perf-time-to-tsc.c | 30 +-
> tools/perf/arch/x86/util/auxtrace.c | 10 +-
> tools/perf/arch/x86/util/intel-bts.c | 38 +-
> tools/perf/arch/x86/util/intel-pt.c | 82 +-
> tools/perf/arch/x86/util/kvm-stat.c | 12 +-
> tools/perf/bench/epoll-ctl.c | 7 +-
> tools/perf/bench/epoll-wait.c | 7 +-
> tools/perf/bench/futex-hash.c | 5 +-
> tools/perf/bench/futex-lock-pi.c | 7 +-
> tools/perf/bench/futex-requeue.c | 7 +-
> tools/perf/bench/futex-wake-parallel.c | 6 +-
> tools/perf/bench/futex-wake.c | 7 +-
> tools/perf/builtin-annotate.c | 16 +-
> tools/perf/builtin-c2c.c | 10 +-
> tools/perf/builtin-diff.c | 20 +-
> tools/perf/builtin-evlist.c | 4 +-
> tools/perf/builtin-ftrace.c | 18 +-
> tools/perf/builtin-inject.c | 60 +-
> tools/perf/builtin-kmem.c | 24 +-
> tools/perf/builtin-kvm.c | 46 +-
> tools/perf/builtin-lock.c | 30 +-
> tools/perf/builtin-mem.c | 2 +-
> tools/perf/builtin-record.c | 50 +-
> tools/perf/builtin-report.c | 32 +-
> tools/perf/builtin-sched.c | 96 +-
> tools/perf/builtin-script.c | 167 +--
> tools/perf/builtin-stat.c | 135 +--
> tools/perf/builtin-timechart.c | 46 +-
> tools/perf/builtin-top.c | 71 +-
> tools/perf/builtin-trace.c | 180 +--
> tools/perf/lib/Build | 12 +
> tools/perf/lib/Documentation/Makefile | 7 +
> tools/perf/lib/Documentation/man/libperf.rst | 102 ++
> tools/perf/lib/Documentation/tutorial/tutorial.rst | 123 ++
> tools/perf/lib/Makefile | 158 +++
> tools/perf/lib/core.c | 34 +
> tools/perf/lib/cpumap.c | 239 ++++
> tools/perf/lib/evlist.c | 159 +++
> tools/perf/lib/evsel.c | 232 ++++
> tools/perf/lib/include/internal/cpumap.h | 17 +
> tools/perf/lib/include/internal/evlist.h | 50 +
> tools/perf/lib/include/internal/evsel.h | 29 +
> tools/perf/lib/include/internal/lib.h | 10 +
> tools/perf/lib/include/internal/tests.h | 19 +
> tools/perf/lib/include/internal/threadmap.h | 23 +
> .../perf/{util => lib/include/internal}/xyarray.h | 6 +-
> tools/perf/lib/include/perf/core.h | 22 +
> tools/perf/lib/include/perf/cpumap.h | 23 +
> tools/perf/lib/include/perf/evlist.h | 35 +
> tools/perf/lib/include/perf/evsel.h | 39 +
> tools/perf/lib/include/perf/threadmap.h | 18 +
> tools/perf/lib/internal.h | 18 +
> tools/perf/lib/lib.c | 46 +
> tools/perf/lib/libperf.map | 40 +
> tools/perf/lib/libperf.pc.template | 11 +
> tools/perf/lib/tests/Makefile | 38 +
> tools/perf/lib/tests/test-cpumap.c | 21 +
> tools/perf/lib/tests/test-evlist.c | 186 +++
> tools/perf/lib/tests/test-evsel.c | 125 ++
> tools/perf/lib/tests/test-threadmap.c | 21 +
> tools/perf/lib/threadmap.c | 81 ++
> tools/perf/lib/xyarray.c | 33 +
> tools/perf/tests/backward-ring-buffer.c | 18 +-
> tools/perf/tests/bitmap.c | 5 +-
> tools/perf/tests/bpf.c | 12 +-
> tools/perf/tests/code-reading.c | 50 +-
> tools/perf/tests/cpumap.c | 21 +-
> tools/perf/tests/event-times.c | 81 +-
> tools/perf/tests/event_update.c | 13 +-
> tools/perf/tests/evsel-roundtrip-name.c | 12 +-
> tools/perf/tests/evsel-tp-sched.c | 8 +-
> tools/perf/tests/hists_cumulate.c | 18 +-
> tools/perf/tests/hists_filter.c | 10 +-
> tools/perf/tests/hists_link.c | 10 +-
> tools/perf/tests/hists_output.c | 20 +-
> tools/perf/tests/keep-tracking.c | 44 +-
> tools/perf/tests/mem2node.c | 5 +-
> tools/perf/tests/mmap-basic.c | 28 +-
> tools/perf/tests/mmap-thread-lookup.c | 4 +-
> tools/perf/tests/openat-syscall-all-cpus.c | 18 +-
> tools/perf/tests/openat-syscall-tp-fields.c | 14 +-
> tools/perf/tests/openat-syscall.c | 10 +-
> tools/perf/tests/parse-events.c | 1220 ++++++++++----------
> tools/perf/tests/parse-no-sample-id-all.c | 6 +-
> tools/perf/tests/perf-record.c | 10 +-
> tools/perf/tests/sample-parsing.c | 8 +-
> tools/perf/tests/sw-clock.c | 33 +-
> tools/perf/tests/switch-tracking.c | 64 +-
> tools/perf/tests/task-exit.c | 35 +-
> tools/perf/tests/thread-map.c | 28 +-
> tools/perf/tests/time-utils-test.c | 2 +-
> tools/perf/tests/topology.c | 9 +-
> tools/perf/ui/browsers/annotate.c | 16 +-
> tools/perf/ui/browsers/hists.c | 54 +-
> tools/perf/ui/browsers/res_sample.c | 4 +-
> tools/perf/ui/browsers/scripts.c | 6 +-
> tools/perf/ui/gtk/annotate.c | 8 +-
> tools/perf/ui/gtk/gtk.h | 8 +-
> tools/perf/ui/gtk/hists.c | 6 +-
> tools/perf/ui/hist.c | 16 +-
> tools/perf/util/Build | 6 -
> tools/perf/util/annotate.c | 42 +-
> tools/perf/util/annotate.h | 26 +-
> tools/perf/util/auxtrace.c | 28 +-
> tools/perf/util/auxtrace.h | 24 +-
> tools/perf/util/bpf-event.c | 2 +-
> tools/perf/util/bpf-event.h | 4 +-
> tools/perf/util/bpf-loader.c | 34 +-
> tools/perf/util/bpf-loader.h | 28 +-
> tools/perf/util/build-id.c | 2 +-
> tools/perf/util/build-id.h | 2 +-
> tools/perf/util/callchain.c | 2 +-
> tools/perf/util/callchain.h | 2 +-
> tools/perf/util/cgroup.c | 22 +-
> tools/perf/util/cgroup.h | 6 +-
> tools/perf/util/counts.c | 17 +-
> tools/perf/util/counts.h | 34 +-
> tools/perf/util/cpumap.c | 264 +----
> tools/perf/util/cpumap.h | 54 +-
> tools/perf/util/cputopo.c | 13 +-
> tools/perf/util/cs-etm.c | 4 +-
> tools/perf/util/data-convert-bt.c | 38 +-
> tools/perf/util/db-export.c | 10 +-
> tools/perf/util/db-export.h | 10 +-
> tools/perf/util/env.c | 2 +-
> tools/perf/util/env.h | 2 +-
> tools/perf/util/event.c | 30 +-
> tools/perf/util/event.h | 14 +-
> tools/perf/util/evlist.c | 607 +++++-----
> tools/perf/util/evlist.h | 215 ++--
> tools/perf/util/evsel.c | 496 ++++----
> tools/perf/util/evsel.h | 194 ++--
> tools/perf/util/evsel_fprintf.c | 16 +-
> tools/perf/util/header.c | 225 ++--
> tools/perf/util/header.h | 24 +-
> tools/perf/util/hist.c | 32 +-
> tools/perf/util/hist.h | 38 +-
> tools/perf/util/intel-bts.c | 22 +-
> tools/perf/util/intel-pt.c | 94 +-
> tools/perf/util/jitdump.c | 8 +-
> tools/perf/util/kvm-stat.h | 22 +-
> tools/perf/util/machine.c | 12 +-
> tools/perf/util/machine.h | 8 +-
> tools/perf/util/map.h | 2 +-
> tools/perf/util/metricgroup.c | 26 +-
> tools/perf/util/metricgroup.h | 6 +-
> tools/perf/util/mmap.c | 4 +-
> tools/perf/util/parse-events.c | 143 +--
> tools/perf/util/parse-events.h | 8 +-
> tools/perf/util/pmu.c | 15 +-
> tools/perf/util/pmu.h | 2 +-
> tools/perf/util/python-ext-sources | 2 -
> tools/perf/util/python.c | 73 +-
> tools/perf/util/record.c | 73 +-
> tools/perf/util/s390-cpumsf.c | 4 +-
> tools/perf/util/s390-sample-raw.c | 6 +-
> tools/perf/util/sample-raw.c | 2 +-
> tools/perf/util/sample-raw.h | 6 +-
> .../perf/util/scripting-engines/trace-event-perl.c | 14 +-
> .../util/scripting-engines/trace-event-python.c | 40 +-
> tools/perf/util/session.c | 81 +-
> tools/perf/util/session.h | 12 +-
> tools/perf/util/setup.py | 3 +-
> tools/perf/util/sort.c | 60 +-
> tools/perf/util/sort.h | 6 +-
> tools/perf/util/stat-display.c | 112 +-
> tools/perf/util/stat-shadow.c | 70 +-
> tools/perf/util/stat.c | 64 +-
> tools/perf/util/stat.h | 35 +-
> tools/perf/util/svghelper.c | 7 +-
> tools/perf/util/thread_map.c | 131 +--
> tools/perf/util/thread_map.h | 58 +-
> tools/perf/util/tool.h | 8 +-
> tools/perf/util/top.c | 12 +-
> tools/perf/util/top.h | 8 +-
> tools/perf/util/trace-event-info.c | 14 +-
> tools/perf/util/trace-event-scripting.c | 2 +-
> tools/perf/util/trace-event.h | 4 +-
> tools/perf/util/util.c | 40 -
> tools/perf/util/util.h | 4 +-
> 189 files changed, 5313 insertions(+), 3819 deletions(-)
> create mode 100644 tools/perf/lib/Build
> create mode 100644 tools/perf/lib/Documentation/Makefile
> create mode 100644 tools/perf/lib/Documentation/man/libperf.rst
> create mode 100644 tools/perf/lib/Documentation/tutorial/tutorial.rst
> create mode 100644 tools/perf/lib/Makefile
> create mode 100644 tools/perf/lib/core.c
> create mode 100644 tools/perf/lib/cpumap.c
> create mode 100644 tools/perf/lib/evlist.c
> create mode 100644 tools/perf/lib/evsel.c
> create mode 100644 tools/perf/lib/include/internal/cpumap.h
> create mode 100644 tools/perf/lib/include/internal/evlist.h
> create mode 100644 tools/perf/lib/include/internal/evsel.h
> create mode 100644 tools/perf/lib/include/internal/lib.h
> create mode 100644 tools/perf/lib/include/internal/tests.h
> create mode 100644 tools/perf/lib/include/internal/threadmap.h
> rename tools/perf/{util => lib/include/internal}/xyarray.h (84%)
> create mode 100644 tools/perf/lib/include/perf/core.h
> create mode 100644 tools/perf/lib/include/perf/cpumap.h
> create mode 100644 tools/perf/lib/include/perf/evlist.h
> create mode 100644 tools/perf/lib/include/perf/evsel.h
> create mode 100644 tools/perf/lib/include/perf/threadmap.h
> create mode 100644 tools/perf/lib/internal.h
> create mode 100644 tools/perf/lib/lib.c
> create mode 100644 tools/perf/lib/libperf.map
> create mode 100644 tools/perf/lib/libperf.pc.template
> create mode 100644 tools/perf/lib/tests/Makefile
> create mode 100644 tools/perf/lib/tests/test-cpumap.c
> create mode 100644 tools/perf/lib/tests/test-evlist.c
> create mode 100644 tools/perf/lib/tests/test-evsel.c
> create mode 100644 tools/perf/lib/tests/test-threadmap.c
> create mode 100644 tools/perf/lib/threadmap.c
> create mode 100644 tools/perf/lib/xyarray.c