[PATCH v1] perf evlist: Warn when 'sleep' workload is used without system-wide (-a) option
Ian Rogers <[email protected]>
| Newsgroups | gmane.linux.kernel,gmane.linux.kernel.perf.user |
|---|---|
| Message-ID | <[email protected]> |
A common mistake when trying to record system-wide profiles for a given duration is running commands like 'perf record sleep 1' or 'perf stat sleep 1' without passing '-a' / '--all-cpus'. When '-a' is omitted, perf defaults to per-process monitoring of the sleep process itself, which does not collect system-wide activity and records very few events. Add a warning in evlist__prepare_workload() when the workload executable is 'sleep' and system-wide mode is not enabled. Signed-off-by: Ian Rogers <[email protected]> --- tools/perf/util/evlist.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index eb7c0d7be064..d53f594ace86 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1562,6 +1562,20 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const int child_ready_pipe[2], go_pipe[2]; char bf; + if (argv && argv[0] && target && !target->system_wide) { + const char *cmd = strrchr(argv[0], '/'); + + if (cmd) + cmd++; + else + cmd = argv[0]; + + if (!strcmp(cmd, "sleep")) { + ui__warning("workload '%s' specified without the system-wide (-a) option\n", + cmd); + } + } + evlist__set_workload_cork_fd(evlist, -1); if (pipe(child_ready_pipe) < 0) { -- 2.55.0.629.g250fe7f194-goog