diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index a5f339d447cc..645dc1828836 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2345,6 +2345,8 @@ int perf_evsel__fprintf(struct perf_evsel *evsel, bool perf_evsel__fallback(struct perf_evsel *evsel, int err, char *msg, size_t msgsize) { + int paranoid; + if ((err == ENOENT || err == ENXIO || err == ENODEV) && evsel->attr.type == PERF_TYPE_HARDWARE && evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) { @@ -2363,6 +2365,22 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err, evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK; zfree(&evsel->name); + return true; + } else if (err == EACCES && !evsel->attr.exclude_kernel && + (paranoid = perf_event_paranoid()) > 1) { + const char *name = perf_evsel__name(evsel); + char *new_name; + + if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : ":") < 0) + return false; + + if (evsel->name) + free(evsel->name); + evsel->name = new_name; + scnprintf(msg, msgsize, +"kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid); + evsel->attr.exclude_kernel = 1; + return true; }