[PATCH v2 2/5] tools/rtla: Replace timerlat_top_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 timerlat_top_usage("...\n") with fatal("...") on errors.

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

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

---

Changes since v1:
- fatal() prints "\n" insteasd of caller as suggested by Crystal Wood
---
 tools/tracing/rtla/src/timerlat_top.c | 28 +++++++++++----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index d8e60f823b25..27b64bdc5b18 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -476,7 +476,7 @@ timerlat_print_stats(struct osnoise_tool *top)
 /*
  * timerlat_top_usage - prints timerlat top usage message
  */
-static void timerlat_top_usage(char *usage)
+static void timerlat_top_usage(void)
 {
 	int i;
 
@@ -524,18 +524,12 @@ static void timerlat_top_usage(char *usage)
 		NULL,
 	};
 
-	if (usage)
-		fprintf(stderr, "%s\n", usage);
-
 	fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
 			VERSION);
 
 	for (i = 0; msg[i]; i++)
 		fprintf(stderr, "%s\n", msg[i]);
 
-	if (usage)
-		exit(EXIT_FAILURE);
-
 	exit(EXIT_SUCCESS);
 }
 
@@ -648,7 +642,7 @@ static struct common_params
 		case 'c':
 			retval = parse_cpu_set(optarg, &params->common.monitored_cpus);
 			if (retval)
-				timerlat_top_usage("\nInvalid -c cpu list\n");
+				fatal("Invalid -c cpu list");
 			params->common.cpus = optarg;
 			break;
 		case 'C':
@@ -667,7 +661,7 @@ static struct common_params
 		case 'd':
 			params->common.duration = parse_seconds_duration(optarg);
 			if (!params->common.duration)
-				timerlat_top_usage("Invalid -d duration\n");
+				fatal("Invalid -d duration");
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
@@ -680,7 +674,7 @@ static struct common_params
 			break;
 		case 'h':
 		case '?':
-			timerlat_top_usage(NULL);
+			timerlat_top_usage();
 			break;
 		case 'H':
 			params->common.hk_cpus = 1;
@@ -700,12 +694,12 @@ static struct common_params
 		case 'p':
 			params->timerlat_period_us = get_llong_from_str(optarg);
 			if (params->timerlat_period_us > 1000000)
-				timerlat_top_usage("Period longer than 1 s\n");
+				fatal("Period longer than 1 s");
 			break;
 		case 'P':
 			retval = parse_prio(optarg, &params->common.sched_param);
 			if (retval == -1)
-				timerlat_top_usage("Invalid -P priority");
+				fatal("Invalid -P priority");
 			params->common.set_sched = 1;
 			break;
 		case 'q':
@@ -740,7 +734,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding trigger %s", optarg);
 			} else {
-				timerlat_top_usage("--trigger requires a previous -e\n");
+				fatal("--trigger requires a previous -e");
 			}
 			break;
 		case '1': /* filter */
@@ -749,7 +743,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding filter %s", optarg);
 			} else {
-				timerlat_top_usage("--filter requires a previous -e\n");
+				fatal("--filter requires a previous -e");
 			}
 			break;
 		case '2': /* dma-latency */
@@ -785,7 +779,7 @@ static struct common_params
 				fatal("Invalid action %s", optarg);
 			break;
 		default:
-			timerlat_top_usage("Invalid option");
+			fatal("Invalid option");
 		}
 	}
 
@@ -802,10 +796,10 @@ static struct common_params
 		params->no_aa = 1;
 
 	if (params->no_aa && params->common.aa_only)
-		timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
+		fatal("--no-aa and --aa-only are mutually exclusive!");
 
 	if (params->common.kernel_workload && params->common.user_workload)
-		timerlat_top_usage("--kernel-threads and --user-threads are mutually exclusive!");
+		fatal("--kernel-threads and --user-threads are mutually exclusive!");
 
 	/*
 	 * If auto-analysis or trace output is enabled, switch from BPF mode to
-- 
2.51.0