perf evlist: Add want_signal parameter to perf_evlist__prepare_workload()

In case a caller doesn't want to receive SIGUSR1 when the child failed
to exec().

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1362987798-24969-6-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -475,7 +475,8 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
 
 	if (forks) {
 		err = perf_evlist__prepare_workload(evsel_list, &opts->target,
-						    argv, opts->pipe_output);
+						    argv, opts->pipe_output,
+						    true);
 		if (err < 0) {
 			pr_err("Couldn't run the workload!\n");
 			goto out_delete_session;

tools/perf/builtin-trace.c

@@ -462,7 +462,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 
 	if (forks) {
 		err = perf_evlist__prepare_workload(evlist, &trace->opts.target,
-						    argv, false);
+						    argv, false, false);
 		if (err < 0) {
 			printf("Couldn't run the workload!\n");
 			goto out_delete_evlist;

tools/perf/tests/perf-record.c

@@ -93,7 +93,8 @@ int test__PERF_RECORD(void)
 	 * so that we have time to open the evlist (calling sys_perf_event_open
 	 * on all the fds) and then mmap them.
 	 */
-	err = perf_evlist__prepare_workload(evlist, &opts.target, argv, false);
+	err = perf_evlist__prepare_workload(evlist, &opts.target, argv,
+					    false, false);
 	if (err < 0) {
 		pr_debug("Couldn't run the workload!\n");
 		goto out_delete_maps;

tools/perf/util/evlist.c

@@ -746,7 +746,8 @@ out_err:
 
 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 				  struct perf_target *target,
-				  const char *argv[], bool pipe_output)
+				  const char *argv[], bool pipe_output,
+				  bool want_signal)
 {
 	int child_ready_pipe[2], go_pipe[2];
 	char bf;
@@ -796,7 +797,8 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 		execvp(argv[0], (char **)argv);
 
 		perror(argv[0]);
-		kill(getppid(), SIGUSR1);
+		if (want_signal)
+			kill(getppid(), SIGUSR1);
 		exit(-1);
 	}
 

tools/perf/util/evlist.h

@@ -87,7 +87,8 @@ void perf_evlist__config(struct perf_evlist *evlist,
 
 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 				  struct perf_target *target,
-				  const char *argv[], bool pipe_output);
+				  const char *argv[], bool pipe_output,
+				  bool want_signal);
 int perf_evlist__start_workload(struct perf_evlist *evlist);
 
 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,