Messages in this thread | | | Date | Sun, 22 Sep 2019 16:47:05 +0200 | From | Jiri Olsa <> | Subject | Re: [RFC 00/73] libperf: Add sampling interface |
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On Fri, Sep 13, 2019 at 03:22:42PM +0200, Jiri Olsa wrote: > 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, so 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
hi, I rebased the branch to latest Arnaldo's perf/core branch
jirka
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