hi, sending changes for exporting basic sampling interface in libperf. It's now possible to use following code in applications via libperf:
--- (example is without error checks for simplicity) struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .sample_period = 1, .wakeup_watermark = 1, .disabled = 1, }; /* ... setup attr */ cpus = perf_cpu_map__new(NULL); evlist = perf_evlist__new(); evsel = perf_evsel__new(&attr); perf_evlist__add(evlist, evsel); perf_evlist__set_maps(evlist, cpus, NULL); err = perf_evlist__open(evlist); err = perf_evlist__mmap(evlist, 4); err = perf_evlist__enable(evlist); /* ... monitored area, plus all the other cpus */ err = perf_evlist__disable(evlist); perf_evlist__for_each_mmap(evlist, map) { if (perf_mmap__read_init(map) < 0) continue; while ((event = perf_mmap__read_event(map)) != NULL) { perf_mmap__consume(map); } perf_mmap__read_done(map); } perf_evlist__delete(evlist); perf_cpu_map__put(cpus); --- (end) Nothing is carved in stone so far, the interface is exported as is available in perf now and we can change it as we want. New tests are added in test-evlist.c to do thread and cpu based sampling. All the functionality should not change, however there's considerable mmap code rewrite. Now we have perf_evlist__mmap_ops called by both perf and libperf mmaps functions with specific 'struct perf_evlist_mmap_ops' callbacks: - get - to get mmap object, both libperf and perf use different objects, because perf needs to carry more data for aio, compression and auxtrace - mmap - to actually mmap the object, it's simple mmap for libperf, but more work for perf wrt aio, compression and auxtrace - idx - callback to get current IDs, used only in perf for auxtrace setup It would be great if guys could run your usual workloads to see if all is fine.. so far so good in my tests ;-) It's also available in here: git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git perf/lib v3 changes: - changed mmap0 and mmap_ovw0 to mmap_first and mmap_ovw_first - rebased to latest perf/core - portion of patches already taken v2 changes: - rebased to latest perf/core - portion of patches already taken - explained mmap refcnt management in following patch changelog: libperf: Centralize map refcnt setting thanks, jirka Cc: Kan Liang <kan.li...@linux.intel.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Ian Rogers <irog...@google.com> Cc: Stephane Eranian <eran...@google.com> Cc: Song Liu <songliubrav...@fb.com> Cc: Alexey Budankov <alexey.budan...@linux.intel.com> Cc: Andi Kleen <a...@linux.intel.com> --- Jiri Olsa (10): libperf: Add perf_evlist__for_each_mmap function libperf: Move mmap allocation to perf_evlist__mmap_ops::get libperf: Move mask setup to perf_evlist__mmap_ops function libperf: Link static tests with libapi.a libperf: Add _GNU_SOURCE define to compilation libperf: Add tests_mmap_thread test libperf: Add tests_mmap_cpus test libperf: Keep count of failed tests libperf: Do not export perf_evsel__init/perf_evlist__init libperf: Add pr_err macro tools/perf/lib/Makefile | 2 ++ tools/perf/lib/evlist.c | 71 ++++++++++++++++++++++++++++++++++++++--------------- tools/perf/lib/include/internal/evlist.h | 3 +++ tools/perf/lib/include/internal/evsel.h | 1 + tools/perf/lib/include/internal/mmap.h | 5 ++-- tools/perf/lib/include/internal/tests.h | 20 ++++++++++++--- tools/perf/lib/include/perf/core.h | 1 + tools/perf/lib/include/perf/evlist.h | 10 +++++++- tools/perf/lib/include/perf/evsel.h | 2 -- tools/perf/lib/internal.h | 3 +++ tools/perf/lib/libperf.map | 3 +-- tools/perf/lib/mmap.c | 6 +++-- tools/perf/lib/tests/Makefile | 8 +++--- tools/perf/lib/tests/test-cpumap.c | 2 +- tools/perf/lib/tests/test-evlist.c | 218 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- tools/perf/lib/tests/test-evsel.c | 2 +- tools/perf/lib/tests/test-threadmap.c | 2 +- tools/perf/util/evlist.c | 29 +++++++++------------- 18 files changed, 333 insertions(+), 55 deletions(-)