[PATCH v2 0/5] tools/rtla: Improve argument processing

[PATCH v2 0/5] tools/rtla: Improve argument processing

[Costa Shulyupin]

The long-term goal of this patch series is to reduce code duplication
and unify argument display and parsing across all four tools.

Costa Shulyupin (5):
  tools/rtla: Add fatal() and replace error handling pattern
  tools/rtla: Replace timerlat_top_usage("...") with fatal("...")
  tools/rtla: Replace timerlat_hist_usage("...") with fatal("...")
  tools/rtla: Replace osnoise_top_usage("...") with fatal("...")
  tools/rtla: Replace osnoise_hist_usage("...") with fatal("...")

 tools/tracing/rtla/src/osnoise_hist.c  | 74 +++++++++--------------
 tools/tracing/rtla/src/osnoise_top.c   | 68 ++++++++-------------
 tools/tracing/rtla/src/timerlat_hist.c | 82 ++++++++++----------------
 tools/tracing/rtla/src/timerlat_top.c  | 76 +++++++++---------------
 tools/tracing/rtla/src/timerlat_u.c    | 12 ++--
 tools/tracing/rtla/src/utils.c         | 15 +++++
 tools/tracing/rtla/src/utils.h         |  1 +
 7 files changed, 128 insertions(+), 200 deletions(-)

-- 
2.51.0

[PATCH v2 1/5] tools/rtla: Add fatal() and replace error handling pattern

[Costa Shulyupin]

The code contains some technical debt in error handling,
which complicates the consolidation of duplicated code.

Introduce an fatal() function to replace the common pattern of
err_msg() followed by exit(EXIT_FAILURE), reducing the length of an
already long function.

Further patches using fatal() follow.

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/osnoise_hist.c  | 42 ++++++++--------------
 tools/tracing/rtla/src/osnoise_top.c   | 42 ++++++++--------------
 tools/tracing/rtla/src/timerlat_hist.c | 50 +++++++++-----------------
 tools/tracing/rtla/src/timerlat_top.c  | 48 +++++++++----------------
 tools/tracing/rtla/src/timerlat_u.c    | 12 +++----
 tools/tracing/rtla/src/utils.c         | 15 ++++++++
 tools/tracing/rtla/src/utils.h         |  1 +
 7 files changed, 81 insertions(+), 129 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index dffb6d0a98d7..31a2c9cf97f5 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -592,10 +592,8 @@ static struct common_params
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
-			if (!tevent) {
-				err_msg("Error alloc trace event");
-				exit(EXIT_FAILURE);
-			}
+			if (!tevent)
+				fatal("Error alloc trace event");
 
 			if (params->common.events)
 				tevent->next = params->common.events;
@@ -615,10 +613,8 @@ static struct common_params
 		case 'H':
 			params->common.hk_cpus = 1;
 			retval = parse_cpu_set(optarg, &params->common.hk_cpu_set);
-			if (retval) {
-				err_msg("Error parsing house keeping CPUs\n");
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Error parsing house keeping CPUs");
 			break;
 		case 'p':
 			params->period = get_llong_from_str(optarg);
@@ -671,10 +667,8 @@ static struct common_params
 		case '4': /* trigger */
 			if (params->common.events) {
 				retval = trace_event_add_trigger(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding trigger %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding trigger %s", optarg);
 			} else {
 				osnoise_hist_usage("--trigger requires a previous -e\n");
 			}
@@ -682,10 +676,8 @@ static struct common_params
 		case '5': /* filter */
 			if (params->common.events) {
 				retval = trace_event_add_filter(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding filter %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding filter %s", optarg);
 			} else {
 				osnoise_hist_usage("--filter requires a previous -e\n");
 			}
@@ -699,18 +691,14 @@ static struct common_params
 		case '8':
 			retval = actions_parse(&params->common.threshold_actions, optarg,
 					       "osnoise_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		case '9':
 			retval = actions_parse(&params->common.end_actions, optarg,
 					       "osnoise_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		default:
 			osnoise_hist_usage("Invalid option");
@@ -720,10 +708,8 @@ static struct common_params
 	if (trace_output)
 		actions_add_trace_output(&params->common.threshold_actions, trace_output);
 
-	if (geteuid()) {
-		err_msg("rtla needs root permission\n");
-		exit(EXIT_FAILURE);
-	}
+	if (geteuid())
+		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");
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 95418f7ecc96..87f282e8c145 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -426,10 +426,8 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
-			if (!tevent) {
-				err_msg("Error alloc trace event");
-				exit(EXIT_FAILURE);
-			}
+			if (!tevent)
+				fatal("Error alloc trace event");
 
 			if (params->common.events)
 				tevent->next = params->common.events;
@@ -443,10 +441,8 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case 'H':
 			params->common.hk_cpus = 1;
 			retval = parse_cpu_set(optarg, &params->common.hk_cpu_set);
-			if (retval) {
-				err_msg("Error parsing house keeping CPUs\n");
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Error parsing house keeping CPUs");
 			break;
 		case 'p':
 			params->period = get_llong_from_str(optarg);
@@ -490,10 +486,8 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case '0': /* trigger */
 			if (params->common.events) {
 				retval = trace_event_add_trigger(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding trigger %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding trigger %s", optarg);
 			} else {
 				osnoise_top_usage(params, "--trigger requires a previous -e\n");
 			}
@@ -501,10 +495,8 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case '1': /* filter */
 			if (params->common.events) {
 				retval = trace_event_add_filter(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding filter %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding filter %s", optarg);
 			} else {
 				osnoise_top_usage(params, "--filter requires a previous -e\n");
 			}
@@ -518,18 +510,14 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case '4':
 			retval = actions_parse(&params->common.threshold_actions, optarg,
 					       "osnoise_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		case '5':
 			retval = actions_parse(&params->common.end_actions, optarg,
 					       "osnoise_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		default:
 			osnoise_top_usage(params, "Invalid option");
@@ -539,10 +527,8 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 	if (trace_output)
 		actions_add_trace_output(&params->common.threshold_actions, trace_output);
 
-	if (geteuid()) {
-		err_msg("osnoise needs root permission\n");
-		exit(EXIT_FAILURE);
-	}
+	if (geteuid())
+		fatal("osnoise needs root permission");
 
 	return &params->common;
 }
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 606c1688057b..ab5d8ca4593c 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -913,10 +913,8 @@ static struct common_params
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
-			if (!tevent) {
-				err_msg("Error alloc trace event");
-				exit(EXIT_FAILURE);
-			}
+			if (!tevent)
+				fatal("Error alloc trace event");
 
 			if (params->common.events)
 				tevent->next = params->common.events;
@@ -936,10 +934,8 @@ static struct common_params
 		case 'H':
 			params->common.hk_cpus = 1;
 			retval = parse_cpu_set(optarg, &params->common.hk_cpu_set);
-			if (retval) {
-				err_msg("Error parsing house keeping CPUs\n");
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Error parsing house keeping CPUs");
 			break;
 		case 'i':
 			params->common.stop_us = get_llong_from_str(optarg);
@@ -1005,10 +1001,8 @@ static struct common_params
 		case '6': /* trigger */
 			if (params->common.events) {
 				retval = trace_event_add_trigger(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding trigger %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding trigger %s", optarg);
 			} else {
 				timerlat_hist_usage("--trigger requires a previous -e\n");
 			}
@@ -1016,20 +1010,16 @@ static struct common_params
 		case '7': /* filter */
 			if (params->common.events) {
 				retval = trace_event_add_filter(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding filter %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding filter %s", optarg);
 			} else {
 				timerlat_hist_usage("--filter requires a previous -e\n");
 			}
 			break;
 		case '8':
 			params->dma_latency = get_llong_from_str(optarg);
-			if (params->dma_latency < 0 || params->dma_latency > 10000) {
-				err_msg("--dma-latency needs to be >= 0 and < 10000");
-				exit(EXIT_FAILURE);
-			}
+			if (params->dma_latency < 0 || params->dma_latency > 10000)
+				fatal("--dma-latency needs to be >= 0 and < 10000");
 			break;
 		case '9':
 			params->no_aa = 1;
@@ -1049,31 +1039,25 @@ static struct common_params
 		case '\5':
 			retval = actions_parse(&params->common.threshold_actions, optarg,
 					       "timerlat_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		case '\6':
 			retval = actions_parse(&params->common.end_actions, optarg,
 					       "timerlat_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		default:
-			timerlat_hist_usage("Invalid option");
+			fatal("Invalid option");
 		}
 	}
 
 	if (trace_output)
 		actions_add_trace_output(&params->common.threshold_actions, trace_output);
 
-	if (geteuid()) {
-		err_msg("rtla needs root permission\n");
-		exit(EXIT_FAILURE);
-	}
+	if (geteuid())
+		fatal("rtla needs root permission");
 
 	if (params->common.hist.no_irq && params->common.hist.no_thread)
 		timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index fc479a0dcb59..d8e60f823b25 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -671,10 +671,8 @@ static struct common_params
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
-			if (!tevent) {
-				err_msg("Error alloc trace event");
-				exit(EXIT_FAILURE);
-			}
+			if (!tevent)
+				fatal("Error alloc trace event");
 
 			if (params->common.events)
 				tevent->next = params->common.events;
@@ -687,10 +685,8 @@ static struct common_params
 		case 'H':
 			params->common.hk_cpus = 1;
 			retval = parse_cpu_set(optarg, &params->common.hk_cpu_set);
-			if (retval) {
-				err_msg("Error parsing house keeping CPUs\n");
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Error parsing house keeping CPUs");
 			break;
 		case 'i':
 			params->common.stop_us = get_llong_from_str(optarg);
@@ -741,10 +737,8 @@ static struct common_params
 		case '0': /* trigger */
 			if (params->common.events) {
 				retval = trace_event_add_trigger(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding trigger %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding trigger %s", optarg);
 			} else {
 				timerlat_top_usage("--trigger requires a previous -e\n");
 			}
@@ -752,20 +746,16 @@ static struct common_params
 		case '1': /* filter */
 			if (params->common.events) {
 				retval = trace_event_add_filter(params->common.events, optarg);
-				if (retval) {
-					err_msg("Error adding filter %s\n", optarg);
-					exit(EXIT_FAILURE);
-				}
+				if (retval)
+					fatal("Error adding filter %s", optarg);
 			} else {
 				timerlat_top_usage("--filter requires a previous -e\n");
 			}
 			break;
 		case '2': /* dma-latency */
 			params->dma_latency = get_llong_from_str(optarg);
-			if (params->dma_latency < 0 || params->dma_latency > 10000) {
-				err_msg("--dma-latency needs to be >= 0 and < 10000");
-				exit(EXIT_FAILURE);
-			}
+			if (params->dma_latency < 0 || params->dma_latency > 10000)
+				fatal("--dma-latency needs to be >= 0 and < 10000");
 			break;
 		case '3': /* no-aa */
 			params->no_aa = 1;
@@ -785,18 +775,14 @@ static struct common_params
 		case '9':
 			retval = actions_parse(&params->common.threshold_actions, optarg,
 					       "timerlat_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		case '\1':
 			retval = actions_parse(&params->common.end_actions, optarg,
 					       "timerlat_trace.txt");
-			if (retval) {
-				err_msg("Invalid action %s\n", optarg);
-				exit(EXIT_FAILURE);
-			}
+			if (retval)
+				fatal("Invalid action %s", optarg);
 			break;
 		default:
 			timerlat_top_usage("Invalid option");
@@ -806,10 +792,8 @@ static struct common_params
 	if (trace_output)
 		actions_add_trace_output(&params->common.threshold_actions, trace_output);
 
-	if (geteuid()) {
-		err_msg("rtla needs root permission\n");
-		exit(EXIT_FAILURE);
-	}
+	if (geteuid())
+		fatal("rtla needs root permission");
 
 	/*
 	 * Auto analysis only happens if stop tracing, thus:
diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index 01dbf9a6b5a5..ce68e39d25fd 100644
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -51,10 +51,8 @@ static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
 
 	if (!params->sched_param) {
 		retval = sched_setscheduler(0, SCHED_FIFO, &sp);
-		if (retval < 0) {
-			err_msg("Error setting timerlat u default priority: %s\n", strerror(errno));
-			exit(1);
-		}
+		if (retval < 0)
+			fatal("Error setting timerlat u default priority: %s", strerror(errno));
 	} else {
 		retval = __set_sched_attr(getpid(), params->sched_param);
 		if (retval) {
@@ -78,10 +76,8 @@ static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
 	snprintf(buffer, sizeof(buffer), "osnoise/per_cpu/cpu%d/timerlat_fd", cpu);
 
 	timerlat_fd = tracefs_instance_file_open(NULL, buffer, O_RDONLY);
-	if (timerlat_fd < 0) {
-		err_msg("Error opening %s:%s\n", buffer, strerror(errno));
-		exit(1);
-	}
+	if (timerlat_fd < 0)
+		fatal("Error opening %s:%s", buffer, strerror(errno));
 
 	debug_msg("User-space timerlat pid %d on cpu %d\n", gettid(), cpu);
 
diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
index d6ab15dcb490..54334c676a22 100644
--- a/tools/tracing/rtla/src/utils.c
+++ b/tools/tracing/rtla/src/utils.c
@@ -56,6 +56,21 @@ void debug_msg(const char *fmt, ...)
 	fprintf(stderr, "%s", message);
 }
 
+/*
+ * fatal - print an error message and EOL to stderr and exit with ERROR
+ */
+void fatal(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+
+	exit(ERROR);
+}
+
 /*
  * get_llong_from_str - get a long long int from a string
  */
diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h
index a2a6f89f342d..1be095f9a7e6 100644
--- a/tools/tracing/rtla/src/utils.h
+++ b/tools/tracing/rtla/src/utils.h
@@ -19,6 +19,7 @@
 extern int config_debug;
 void debug_msg(const char *fmt, ...);
 void err_msg(const char *fmt, ...);
+void fatal(const char *fmt, ...);
 
 long parse_seconds_duration(char *val);
 void get_duration(time_t start_time, char *output, int output_size);
-- 
2.51.0

[PATCH v2 2/5] tools/rtla: Replace timerlat_top_usage("...") with fatal("...")

[Costa Shulyupin]

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

[PATCH v2 3/5] tools/rtla: Replace timerlat_hist_usage("...") with fatal("...")

[Costa Shulyupin]

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_hist_usage("...\n") with fatal("...") on errors.

Remove the already unused 'usage' argument from timerlat_hist_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_hist.c | 32 +++++++++++---------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index ab5d8ca4593c..71557f5751a6 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -710,7 +710,7 @@ timerlat_print_stats(struct osnoise_tool *tool)
 /*
  * timerlat_hist_usage - prints timerlat top usage message
  */
-static void timerlat_hist_usage(char *usage)
+static void timerlat_hist_usage(void)
 {
 	int i;
 
@@ -766,18 +766,12 @@ static void timerlat_hist_usage(char *usage)
 		NULL,
 	};
 
-	if (usage)
-		fprintf(stderr, "%s\n", usage);
-
 	fprintf(stderr, "rtla timerlat hist: a per-cpu histogram 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);
 }
 
@@ -884,7 +878,7 @@ static struct common_params
 		case 'c':
 			retval = parse_cpu_set(optarg, &params->common.monitored_cpus);
 			if (retval)
-				timerlat_hist_usage("\nInvalid -c cpu list\n");
+				fatal("Invalid -c cpu list");
 			params->common.cpus = optarg;
 			break;
 		case 'C':
@@ -901,7 +895,7 @@ 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)
-				timerlat_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
+				fatal("Bucket size needs to be > 0 and <= 1000000");
 			break;
 		case 'D':
 			config_debug = 1;
@@ -909,7 +903,7 @@ static struct common_params
 		case 'd':
 			params->common.duration = parse_seconds_duration(optarg);
 			if (!params->common.duration)
-				timerlat_hist_usage("Invalid -D duration\n");
+				fatal("Invalid -D duration");
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
@@ -925,11 +919,11 @@ static struct common_params
 			params->common.hist.entries = get_llong_from_str(optarg);
 			if (params->common.hist.entries < 10 ||
 			    params->common.hist.entries > 9999999)
-				timerlat_hist_usage("Entries must be > 10 and < 9999999\n");
+				fatal("Entries must be > 10 and < 9999999");
 			break;
 		case 'h':
 		case '?':
-			timerlat_hist_usage(NULL);
+			timerlat_hist_usage();
 			break;
 		case 'H':
 			params->common.hk_cpus = 1;
@@ -949,12 +943,12 @@ static struct common_params
 		case 'p':
 			params->timerlat_period_us = get_llong_from_str(optarg);
 			if (params->timerlat_period_us > 1000000)
-				timerlat_hist_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_hist_usage("Invalid -P priority");
+				fatal("Invalid -P priority");
 			params->common.set_sched = 1;
 			break;
 		case 's':
@@ -1004,7 +998,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding trigger %s", optarg);
 			} else {
-				timerlat_hist_usage("--trigger requires a previous -e\n");
+				fatal("--trigger requires a previous -e");
 			}
 			break;
 		case '7': /* filter */
@@ -1013,7 +1007,7 @@ static struct common_params
 				if (retval)
 					fatal("Error adding filter %s", optarg);
 			} else {
-				timerlat_hist_usage("--filter requires a previous -e\n");
+				fatal("--filter requires a previous -e");
 			}
 			break;
 		case '8':
@@ -1060,10 +1054,10 @@ static struct common_params
 		fatal("rtla needs root permission");
 
 	if (params->common.hist.no_irq && params->common.hist.no_thread)
-		timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
+		fatal("no-irq and no-thread set, there is nothing to do here");
 
 	if (params->common.hist.no_index && !params->common.hist.with_zeros)
-		timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");
+		fatal("no-index set with with-zeros is not set - it does not make sense");
 
 	/*
 	 * Auto analysis only happens if stop tracing, thus:
@@ -1072,7 +1066,7 @@ static struct common_params
 		params->no_aa = 1;
 
 	if (params->common.kernel_workload && params->common.user_workload)
-		timerlat_hist_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

[PATCH v2 4/5] tools/rtla: Replace osnoise_top_usage("...") with fatal("...")

[Costa Shulyupin]

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_top_usage("...") with fatal("...") on errors.

Remove the already unused 'usage' argument from osnoise_top_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_top.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 87f282e8c145..f0782c5ed0b1 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -257,7 +257,7 @@ osnoise_print_stats(struct osnoise_tool *top)
 /*
  * osnoise_top_usage - prints osnoise top usage message
  */
-static void osnoise_top_usage(struct osnoise_params *params, char *usage)
+static void osnoise_top_usage(struct osnoise_params *params)
 {
 	int i;
 
@@ -296,9 +296,6 @@ static void osnoise_top_usage(struct osnoise_params *params, char *usage)
 		NULL,
 	};
 
-	if (usage)
-		fprintf(stderr, "%s\n", usage);
-
 	if (params->mode == MODE_OSNOISE) {
 		fprintf(stderr,
 			"rtla osnoise top: a per-cpu summary of the OS noise (version %s)\n",
@@ -318,9 +315,6 @@ static void osnoise_top_usage(struct osnoise_params *params, char *usage)
 	for (i = 0; msg[i]; i++)
 		fprintf(stderr, "%s\n", msg[i]);
 
-	if (usage)
-		exit(EXIT_FAILURE);
-
 	exit(EXIT_SUCCESS);
 }
 
@@ -403,7 +397,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case 'c':
 			retval = parse_cpu_set(optarg, &params->common.monitored_cpus);
 			if (retval)
-				osnoise_top_usage(params, "\nInvalid -c cpu list\n");
+				fatal("Invalid -c cpu list");
 			params->common.cpus = optarg;
 			break;
 		case 'C':
@@ -422,7 +416,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case 'd':
 			params->common.duration = parse_seconds_duration(optarg);
 			if (!params->common.duration)
-				osnoise_top_usage(params, "Invalid -d duration\n");
+				fatal("Invalid -d duration");
 			break;
 		case 'e':
 			tevent = trace_event_alloc(optarg);
@@ -436,7 +430,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 			break;
 		case 'h':
 		case '?':
-			osnoise_top_usage(params, NULL);
+			osnoise_top_usage(params);
 			break;
 		case 'H':
 			params->common.hk_cpus = 1;
@@ -447,12 +441,12 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case 'p':
 			params->period = get_llong_from_str(optarg);
 			if (params->period > 10000000)
-				osnoise_top_usage(params, "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_top_usage(params, "Invalid -P priority");
+				fatal("Invalid -P priority");
 			params->common.set_sched = 1;
 			break;
 		case 'q':
@@ -461,7 +455,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 		case 'r':
 			params->runtime = get_llong_from_str(optarg);
 			if (params->runtime < 100)
-				osnoise_top_usage(params, "Runtime shorter than 100 us\n");
+				fatal("Runtime shorter than 100 us");
 			break;
 		case 's':
 			params->common.stop_us = get_llong_from_str(optarg);
@@ -489,7 +483,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 				if (retval)
 					fatal("Error adding trigger %s", optarg);
 			} else {
-				osnoise_top_usage(params, "--trigger requires a previous -e\n");
+				fatal("--trigger requires a previous -e");
 			}
 			break;
 		case '1': /* filter */
@@ -498,7 +492,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 				if (retval)
 					fatal("Error adding filter %s", optarg);
 			} else {
-				osnoise_top_usage(params, "--filter requires a previous -e\n");
+				fatal("--filter requires a previous -e");
 			}
 			break;
 		case '2':
@@ -520,7 +514,7 @@ struct common_params *osnoise_top_parse_args(int argc, char **argv)
 				fatal("Invalid action %s", optarg);
 			break;
 		default:
-			osnoise_top_usage(params, "Invalid option");
+			fatal("Invalid option");
 		}
 	}
 
-- 
2.51.0

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

[Costa Shulyupin]

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

Re: [PATCH v2 0/5] tools/rtla: Improve argument processing

[Tomas Glozar]

so 11. 10. 2025 v 10:28 odesílatel Costa Shulyupin
<costa.shul@redhat.com> napsal:
>
> The long-term goal of this patch series is to reduce code duplication
> and unify argument display and parsing across all four tools.
>
> Costa Shulyupin (5):
>   tools/rtla: Add fatal() and replace error handling pattern
>   tools/rtla: Replace timerlat_top_usage("...") with fatal("...")
>   tools/rtla: Replace timerlat_hist_usage("...") with fatal("...")
>   tools/rtla: Replace osnoise_top_usage("...") with fatal("...")
>   tools/rtla: Replace osnoise_hist_usage("...") with fatal("...")

It's perhaps unnecessary to do one commit per <tool>_usage() change.
On the other hand, separating changes like this helps backporting (not
much relevant here but relevant in other case).

>
>  tools/tracing/rtla/src/osnoise_hist.c  | 74 +++++++++--------------
>  tools/tracing/rtla/src/osnoise_top.c   | 68 ++++++++-------------
>  tools/tracing/rtla/src/timerlat_hist.c | 82 ++++++++++----------------
>  tools/tracing/rtla/src/timerlat_top.c  | 76 +++++++++---------------
>  tools/tracing/rtla/src/timerlat_u.c    | 12 ++--
>  tools/tracing/rtla/src/utils.c         | 15 +++++
>  tools/tracing/rtla/src/utils.h         |  1 +
>  7 files changed, 128 insertions(+), 200 deletions(-)
>
> --
> 2.51.0
>

Otherwise, I agree. Especially the timerlat tools have so many
arguments that for a typical terminal size, you won't even see the
error message, as it will be pushed outside the view. I was not even
aware RTLA prints error messages in some of those cases, I thought it
just prints the help for some time.

For entire patchset:

Reviewed-by: Tomas Glozar <tglozar@redhat.com>

Tomas