[PATCH 23/23] perf trace: Add -q/--quiet option

[Namhyung Kim <namhyung@kernel.org>]

The -q/--quiet option is to suppress any message.  Sometimes users just
want to run the command and it can be used for that case.

Also check the quiet variable when printing error messages.

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-trace.txt |  4 ++++
 tools/perf/builtin-trace.c              | 33 ++++++++++++++++++++++-----------
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index afd728672b6f..4ac21b6194e7 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -70,6 +70,10 @@ filter out the startup phase of the program, which is often very different.
 --verbose=::
         Verbosity level.
 
+-q::
+--quiet::
+	Do not show any message.  (Suppress -v)
+
 --no-inherit::
 	Child tasks do not inherit counters.
 
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 256f1fac6f7e..00e1349c73bf 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1242,7 +1242,7 @@ static int trace__validate_ev_qualifier(struct trace *trace)
 	trace->ev_qualifier_ids.entries = malloc(trace->ev_qualifier_ids.nr *
 						 sizeof(trace->ev_qualifier_ids.entries[0]));
 
-	if (trace->ev_qualifier_ids.entries == NULL) {
+	if (trace->ev_qualifier_ids.entries == NULL && !quiet) {
 		fputs("Error:\tNot enough memory for allocating events qualifier ids\n",
 		       trace->output);
 		err = -EINVAL;
@@ -1257,7 +1257,8 @@ static int trace__validate_ev_qualifier(struct trace *trace)
 
 		if (id < 0) {
 			if (err == 0) {
-				fputs("Error:\tInvalid syscall ", trace->output);
+				if (!quiet)
+					fputs("Error:\tInvalid syscall ", trace->output);
 				err = -EINVAL;
 			} else {
 				fputs(", ", trace->output);
@@ -1270,8 +1271,10 @@ static int trace__validate_ev_qualifier(struct trace *trace)
 	}
 
 	if (err < 0) {
-		fputs("\nHint:\ttry 'perf list syscalls:sys_enter_*'"
-		      "\nHint:\tand: 'man syscalls'\n", trace->output);
+		if (verbose >= 0) {
+			fputs("\nHint:\ttry 'perf list syscalls:sys_enter_*'"
+			      "\nHint:\tand: 'man syscalls'\n", trace->output);
+		}
 		zfree(&trace->ev_qualifier_ids.entries);
 		trace->ev_qualifier_ids.nr = 0;
 	}
@@ -2604,7 +2607,7 @@ static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp)
 	size_t printed = trace__fprintf_threads_header(fp);
 	struct rb_node *nd;
 
-	if (threads == NULL) {
+	if (threads == NULL && !quiet) {
 		fprintf(fp, "%s", "Error sorting output by nr_events!\n");
 		return 0;
 	}
@@ -2761,7 +2764,7 @@ static int trace__parse_events_option(const struct option *opt, const char *str,
 		};
 
 		trace->ev_qualifier = strlist__new(lists[1], &slist_config);
-		if (trace->ev_qualifier == NULL) {
+		if (trace->ev_qualifier == NULL && !quiet) {
 			fputs("Not enough memory to parse event qualifier", trace->output);
 			goto out;
 		}
@@ -2849,6 +2852,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 		     trace__set_duration),
 	OPT_BOOLEAN(0, "sched", &trace.sched, "show blocking scheduler events"),
 	OPT_INCR('v', "verbose", &verbose, "be more verbose"),
+	OPT_BOOLEAN('q', "quiet", &quiet, "Do not show any message"),
 	OPT_BOOLEAN('T', "time", &trace.full_time,
 		    "Show full timestamp, not time relative to first start"),
 	OPT_BOOLEAN('s', "summary", &trace.summary_only,
@@ -2898,6 +2902,8 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	argc = parse_options_subcommand(argc, argv, trace_options, trace_subcommands,
 				 trace_usage, PARSE_OPT_STOP_AT_NON_OPTION);
+	if (quiet)
+		perf_quiet_option();
 
 	err = bpf__setup_stdout(trace.evlist);
 	if (err) {
@@ -2957,7 +2963,8 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (output_name != NULL) {
 		err = trace__open_output(&trace, output_name);
 		if (err < 0) {
-			perror("failed to create output file");
+			pr_err("failed to create output file: %s\n",
+			       str_error_r(errno, bf, sizeof(bf)));
 			goto out;
 		}
 	}
@@ -2966,15 +2973,19 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	err = target__validate(&trace.opts.target);
 	if (err) {
-		target__strerror(&trace.opts.target, err, bf, sizeof(bf));
-		fprintf(trace.output, "%s", bf);
+		if (!quiet) {
+			target__strerror(&trace.opts.target, err, bf, sizeof(bf));
+			fprintf(trace.output, "%s", bf);
+		}
 		goto out_close;
 	}
 
 	err = target__parse_uid(&trace.opts.target);
 	if (err) {
-		target__strerror(&trace.opts.target, err, bf, sizeof(bf));
-		fprintf(trace.output, "%s", bf);
+		if (!quiet) {
+			target__strerror(&trace.opts.target, err, bf, sizeof(bf));
+			fprintf(trace.output, "%s", bf);
+		}
 		goto out_close;
 	}
 
-- 
2.11.0