From: Dmitrii Dolgov <9erthalion6@gmail.com> mainline inclusion from mainline-v6.4-rc1 commit ecc68ee216c6c5b2f84915e1441adf436f1b019b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICDP8O Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- It seems that perf stat -b <prog id> doesn't produce any results: $ perf stat -e cycles -b 4 -I 10000 -vvv Control descriptor is not initialized cycles: 0 0 0 time counts unit events 10.007641640 <not supported> cycles Looks like this happens because fentry/fexit progs are getting loaded, but the corresponding perf event is not enabled and not added into the events bpf map. I think there is some mixing up between two type of bpf support, one for bperf and one for bpf_profiler. Both are identified via evsel__is_bpf, based on which perf events are enabled, but for the latter (bpf_profiler) a perf event is required. Using evsel__is_bperf to check only bperf produces expected results: $ perf stat -e cycles -b 4 -I 10000 -vvv Control descriptor is not initialized ------------------------------------------------------------ perf_event_attr: size 136 sample_type IDENTIFIER read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING disabled 1 exclude_guest 1 ------------------------------------------------------------ sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ [...perf_event_attr for other CPUs...] ------------------------------------------------------------ cycles: 309426 169009 169009 time counts unit events 10.010091271 309426 cycles The final numbers correspond (at least in the level of magnitude) to the same metric obtained via bpftool. Fixes: 112cb56164bc2108 ("perf stat: Introduce config stat.bpf-counter-events") Reviewed-by: Song Liu <song@kernel.org> Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com> Tested-by: Song Liu <song@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230412182316.11628-1-9erthalion6@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Xiaomeng Zhang <zhangxiaomeng13@huawei.com> --- tools/perf/builtin-stat.c | 4 ++-- tools/perf/util/evsel.h | 5 +++++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index e96d5e92a07b..babe763c3837 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -780,7 +780,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) evlist__for_each_entry(evsel_list, counter) { if (bpf_counter__load(counter, &target)) return -1; - if (!evsel__is_bpf(counter)) + if (!(evsel__is_bperf(counter))) all_counters_use_bpf = false; } @@ -798,7 +798,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) continue; if (counter->reset_group || counter->errored) continue; - if (evsel__is_bpf(counter)) + if (evsel__is_bperf(counter)) continue; try_again: if (create_perf_stat_counter(counter, &stat_config, &target, diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 2420417dbcec..ce67bdbbeb4e 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -246,6 +246,11 @@ static inline bool evsel__is_bpf(struct evsel *evsel) return evsel->bpf_counter_ops != NULL; } +static inline bool evsel__is_bperf(struct evsel *evsel) +{ + return evsel->bpf_counter_ops != NULL && list_empty(&evsel->bpf_counter_list); +} + #define EVSEL__MAX_ALIASES 8 extern const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX][EVSEL__MAX_ALIASES]; -- 2.34.1