[PATCH v2 5/5] tools/rtla: Replace osnoise_hist_usage("...") with fatal("...")

[Costa Shulyupin <costa.shul@redhat.com>]

A long time ago, when the usage help was short, it was a favor
to the user to show it on error. Now that the usage help has
become very long, it is too noisy to dump the complete help text
for each typo after the error message itself.

Replace osnoise_hist_usage("...") with fatal("...") on errors.

Remove the already unused 'usage' argument from osnoise_hist_usage().

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>

---

Changes since v1:
- fatal() prints "\n" insteasd of caller as suggested Crystal Wood
---
 tools/tracing/rtla/src/osnoise_hist.c | 32 +++++++++++----------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 31a2c9cf97f5..b0b7f04c3871 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -421,7 +421,7 @@ osnoise_print_stats(struct osnoise_tool *tool)
 /*
  * osnoise_hist_usage - prints osnoise hist usage message
  */
-static void osnoise_hist_usage(char *usage)
+static void osnoise_hist_usage(void)
 {
 	int i;
 
@@ -467,18 +467,12 @@ static void osnoise_hist_usage(char *usage)
 		NULL,
 	};
 
-	if (usage)
-		fprintf(stderr, "%s\n", usage);
-
 	fprintf(stderr, "rtla osnoise hist: a per-cpu histogram of the OS noise (version %s)\n",
 			VERSION);
 
 	for (i = 0; msg[i]; i++)
 		fprintf(stderr, "%s\n", msg[i]);
 
-	if (usage)
-		exit(EXIT_FAILURE);
-
 	exit(EXIT_SUCCESS);
 }
 
@@ -564,12 +558,12 @@ static struct common_params
 			params->common.hist.bucket_size = get_llong_from_str(optarg);
 			if (params->common.hist.bucket_size == 0 ||
 			    params->common.hist.bucket_size >= 1000000)
-				osnoise_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
+				fatal("Bucket size needs to be > 0 and <= 1000000");
 			break;
 		case 'c':
 			retval = parse_cpu_set(optarg, &params->common.monitored_cpus);
 			if (retval)
-				osnoise_hist_usage("\nInvalid -c cpu list\n");
+				fatal("Invalid -c cpu list");
 			params->common.cpus = optarg;
 			break;
 		case 'C':
@@ -588,7 +582,7 @@ static struct common_params
 		case 'd':
 			params->common.duration = parse_seconds_duration(optarg);
 			if (!params->common.duration)
-				osnoise_hist_usage("Invalid -D duration\n");
+				fatal("Invalid -D duration");
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
@@ -604,11 +598,11 @@ static struct common_params
 			params->common.hist.entries = get_llong_from_str(optarg);
 			if (params->common.hist.entries < 10 ||
 			    params->common.hist.entries > 9999999)
-				osnoise_hist_usage("Entries must be > 10 and < 9999999\n");
+				fatal("Entries must be > 10 and < 9999999");
 			break;
 		case 'h':
 		case '?':
-			osnoise_hist_usage(NULL);
+			osnoise_hist_usage();
 			break;
 		case 'H':
 			params->common.hk_cpus = 1;
@@ -619,18 +613,18 @@ static struct common_params
 		case 'p':
 			params->period = get_llong_from_str(optarg);
 			if (params->period > 10000000)
-				osnoise_hist_usage("Period longer than 10 s\n");
+				fatal("Period longer than 10 s");
 			break;
 		case 'P':
 			retval = parse_prio(optarg, &params->common.sched_param);
 			if (retval == -1)
-				osnoise_hist_usage("Invalid -P priority");
+				fatal("Invalid -P priority");
 			params->common.set_sched = 1;
 			break;
 		case 'r':
 			params->runtime = get_llong_from_str(optarg);
 			if (params->runtime < 100)
-				osnoise_hist_usage("Runtime shorter than 100 us\n");
+				fatal("Runtime shorter than 100 us");
 			break;
 		case 's':
 			params->common.stop_us = get_llong_from_str(optarg);
@@ -670,7 +664,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding trigger %s", optarg);
 			} else {
-				osnoise_hist_usage("--trigger requires a previous -e\n");
+				fatal("--trigger requires a previous -e");
 			}
 			break;
 		case '5': /* filter */
@@ -679,7 +673,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding filter %s", optarg);
 			} else {
-				osnoise_hist_usage("--filter requires a previous -e\n");
+				fatal("--filter requires a previous -e");
 			}
 			break;
 		case '6':
@@ -701,7 +695,7 @@ static struct common_params
 				fatal("Invalid action %s", optarg);
 			break;
 		default:
-			osnoise_hist_usage("Invalid option");
+			fatal("Invalid option");
 		}
 	}
 
@@ -712,7 +706,7 @@ static struct common_params
 		fatal("rtla needs root permission");
 
 	if (params->common.hist.no_index && !params->common.hist.with_zeros)
-		osnoise_hist_usage("no-index set and with-zeros not set - it does not make sense");
+		fatal("no-index set and with-zeros not set - it does not make sense");
 
 	return &params->common;
 }
-- 
2.51.0