diff options
Diffstat (limited to 'tools/perf/util/evsel.c')
| -rw-r--r-- | tools/perf/util/evsel.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 738ce22..645dc18 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2345,6 +2345,8 @@ out: 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) { @@ -2364,6 +2366,22 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err, 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; } return false; @@ -2382,12 +2400,13 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n" "which controls use of the performance events system by\n" "unprivileged users (without CAP_SYS_ADMIN).\n\n" - "The default value is 1:\n\n" + "The current value is %d:\n\n" " -1: Allow use of (almost) all events by all users\n" ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n" ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n" ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN", - target->system_wide ? "system-wide " : ""); + target->system_wide ? "system-wide " : "", + perf_event_paranoid()); case ENOENT: return scnprintf(msg, size, "The %s event is not supported.", perf_evsel__name(evsel)); |