V2: cyclictest: clean up getopt_long() parameters

V2: suggested by "Luis Claudio R. Goncalves" <[email protected]>
Change iterations over calling clock_gettime() from a loop count to a time duration.

cyclictest: ARM panda clock resolution will be ~30 usec unless CONFIG_OMAP_32K_TIMER=n, resulting in a poor latency report.

This patch does _not_ fix the problem, it merely provides the instrumentation to make it visible. The value of measured resolution is useful information for any system.

Signed-off-by Frank Rowand <[email protected]>

---
src/cyclictest/cyclictest.c | 110 109 + 1 - 0 !

 1 file changed, 109 insertions(+), 1 deletion(-)

Index: b/src/cyclictest/cyclictest.c
===================================================================

src/cyclictest/cyclictest.c +104 -1

@@ -174,6 +174,8 @@ static int use_nsecs = 0;
 static int refresh_on_max;
 static int force_sched_other;
 static int priospread = 0;
+static int check_clock_resolution;
+static int ct_debug;
 
 static pthread_cond_t refresh_on_max_cond = PTHREAD_COND_INITIALIZER;
 static pthread_mutex_t refresh_on_max_lock = PTHREAD_MUTEX_INITIALIZER;

@@ -944,6 +946,9 @@ static void display_help(int error)
 	       "-q       --quiet           print only a summary on exit\n"
 	       "-Q       --priospread       spread priority levels starting at specified value\n"
 	       "-r       --relative        use relative timer instead of absolute\n"
+	       "-R       --resolution      check clock resolution, calling clock_gettime() many\n"
+	       "                           times.  list of clock_gettime() values will be\n"
+	       "                           reported with -X\n"
 	       "-s       --system          use sys_nanosleep and sys_setitimer\n"
 	       "-S       --smp             Standard SMP testing: options -a -t -n and\n"
 	       "                           same priority of all threads\n"

@@ -960,6 +965,7 @@ static void display_help(int error)
 	       "                           format: n:c:v n=tasknum c=count v=value in us\n"
 	       "-w       --wakeup          task wakeup tracing (used with -b)\n"
 	       "-W       --wakeuprt        rt task wakeup tracing (used with -b)\n"
+	       "-X       --dbg_cyclictest  print info useful for debugging cyclictest\n"
 	       "-y POLI  --policy=POLI     policy of realtime thread, POLI may be fifo(default) or rr\n"
 	       "                           format: --policy=fifo(default) or --policy=rr\n",
 	       tracers

@@ -1076,6 +1082,7 @@ static void process_options (int argc, c
 			{"quiet",            no_argument,       NULL, 'q'},
 			{"priospread",       no_argument,       NULL, 'Q'},
 			{"relative",         no_argument,       NULL, 'r'},
+			{"resolution",       no_argument,       NULL, 'R'},
 			{"system",           no_argument,       NULL, 's'},
 			{"smp",              no_argument,       NULL, 'S'},
 			{"threads",          optional_argument, NULL, 't'},

@@ -1085,11 +1092,12 @@ static void process_options (int argc, c
 			{"verbose",          no_argument,       NULL, 'v'},
 			{"wakeup",           no_argument,       NULL, 'w'},
 			{"wakeuprt",         no_argument,       NULL, 'W'},
+			{"dbg_cyclictest",   no_argument,       NULL, 'X'},
 			{"policy",           required_argument, NULL, 'y'},
 			{"help",             no_argument,       NULL, '?'},
 			{NULL, 0, NULL, 0}
 		};
-		int c = getopt_long(argc, argv, "a::b:Bc:Cd:D:e:Efh:H:i:Il:MnNo:O:p:PmqQrsSt::uUvD:wWT:y:",
+		int c = getopt_long(argc, argv, "a::b:Bc:Cd:D:e:Efh:H:i:Il:MnNo:O:p:PmqQrRsSt::uUvD:wWXT:y:",
 				    long_options, &option_index);
 		if (c == -1)
 			break;

@@ -1158,6 +1166,7 @@ static void process_options (int argc, c
 		case 'q': quiet = 1; break;
 		case 'Q': priospread = 1; break;
 		case 'r': timermode = TIMER_RELTIME; break;
+		case 'R': check_clock_resolution = 1; break;
 		case 's': use_system = MODE_SYS_OFFSET; break;
 		case 'S':  /* SMP testing */
 			if (numa)

@@ -1202,6 +1211,7 @@ static void process_options (int argc, c
 		case 'v': verbose = 1; break;
 		case 'w': tracetype = WAKEUP; break;
 		case 'W': tracetype = WAKEUPRT; break;
+		case 'X': ct_debug = 1; break;
 		case 'y': handlepolicy(optarg); break;
 
 		case '?': display_help(0); break;

@@ -1483,6 +1493,104 @@ int main(int argc, char **argv)
 	if (check_timer())
 		warn("High resolution timers not available\n");
 
+	if (check_clock_resolution) {
+		int clock;
+		uint64_t diff;
+		int k;
+		uint64_t min_non_zero_diff = UINT64_MAX;
+		struct timespec now;
+		struct timespec prev;
+		uint64_t reported_resolution = UINT64_MAX;
+		struct timespec res;
+		struct timespec *time;
+		int times;
+		int zero_diff = 0;
+
+		clock = clocksources[clocksel];
+
+		if (clock_getres(clock, &res)) {
+			warn("clock_getres failed");
+		} else {
+			reported_resolution = (NSEC_PER_SEC * res.tv_sec) + res.tv_nsec;
+		}
+
+
+		/*
+		 * Calculate how many calls to clock_gettime are needed.
+		 * Then call it that many times.
+		 * Goal is to collect timestamps for ~ 0.001 sec.
+		 * This will reliably capture resolution <= 500 usec.
+		 */
+		times = 1000;
+		clock_gettime(clock, &prev);
+		for (k=0; k < times; k++) {
+			clock_gettime(clock, &now);
+		}
+
+		diff = calcdiff_ns(now, prev);
+		if (diff == 0) {
+			/*
+			 * No clock rollover occurred.
+			 * Use the default value for times.
+			 */
+			times = -1;
+		} else {
+			int call_time;
+			call_time = diff / times;         /* duration 1 call */
+			times = NSEC_PER_SEC / call_time; /* calls per second */
+			times /= 1000;                    /* calls per msec */
+			if (times < 1000)
+				times = 1000;
+		}
+		/* sanity check */
+		if ((times <= 0) || (times > 100000))
+			times = 100000;
+
+		time = calloc(times, sizeof(*time));
+
+		for (k=0; k < times; k++) {
+			clock_gettime(clock, &time[k]);
+		}
+
+		if (ct_debug) {
+			fprintf(stderr, "\n\nFor %d consecutive calls to clock_gettime():\n\n", times);
+			fprintf(stderr, "time, delta time (nsec)\n\n");
+		}
+
+		prev = time[0];
+		for (k=1; k < times; k++) {
+
+			diff = calcdiff_ns(time[k], prev);
+			prev = time[k];
+
+			if (diff == 0) {
+				zero_diff = 1;
+			} else if (diff < min_non_zero_diff) {
+				min_non_zero_diff = diff;
+			}
+
+			if (ct_debug)
+				fprintf(stderr, "%ld.%06ld  %5llu\n", time[k].tv_sec, time[k].tv_nsec, diff);
+		}
+
+		free(time);
+
+
+		if (verbose ||
+		    (min_non_zero_diff && (min_non_zero_diff > reported_resolution))) {
+		    	/*
+			 * Measured clock resolution includes the time to call
+			 * clock_gettime(), so it will be slightly larger than
+			 * actual resolution.
+			 */
+			fprintf(stderr, "reported clock resolution: %lld nsec\n",
+				reported_resolution);
+			fprintf(stderr, "measured clock resolution approximately: %llu nsec\n",

cyclictest getopt_long() parameter clean up.
Clean up before following patch which will add a new option.

Some elements of long_options were not in alphabetical order.

Some elements of optstring were not in alphabetical order.

'-e', '--latency' was missing help text

short form of --duration ('D') was missing from optstring

Change a few instances of leading spaces to tabs.

Add white space to long_options to improve readability.

Some cases of the switch processing the result of
getopt_long() were not in alphabetical order.

Did _not_ clean up option value parsing and processing.

Signed-off-by Frank Rowand <[email protected]>

---
src/cyclictest/cyclictest.c | 143 73 + 70 - 0 !

 1 file changed, 73 insertions(+), 70 deletions(-)

Index: b/src/cyclictest/cyclictest.c
===================================================================

src/cyclictest/cyclictest.c +69 -67

@@ -923,10 +923,11 @@ static void display_help(int error)
 	       "-D       --duration=t      specify a length for the test run\n"
 	       "                           default is in seconds, but 'm', 'h', or 'd' maybe added\n"
 	       "                           to modify value to minutes, hours or days\n"
+	       "-e       --latency=PM_QOS  write PM_QOS to /dev/cpu_dma_latency\n"
 	       "-E       --event           event tracing (used with -b)\n"
 	       "-f       --ftrace          function trace (when -b is active)\n"
 	       "-h       --histogram=US    dump a latency histogram to stdout after the run\n"
-               "                           (with same priority about many threads)\n"
+	       "                           (with same priority about many threads)\n"
 	       "                           US is the max time to be be tracked in microseconds\n"
 	       "-H       --histofall=US    same as -h except with an additional summary column\n"
 	       "-i INTV  --interval=INTV   base interval of thread in us default=1000\n"

@@ -944,6 +945,8 @@ static void display_help(int error)
 	       "-Q       --priospread       spread priority levels starting at specified value\n"
 	       "-r       --relative        use relative timer instead of absolute\n"
 	       "-s       --system          use sys_nanosleep and sys_setitimer\n"
+	       "-S       --smp             Standard SMP testing: options -a -t -n and\n"
+	       "                           same priority of all threads\n"
 	       "-t       --threads         one thread per available processor\n"
 	       "-t [NUM] --threads=NUM     number of threads:\n"
 	       "                           without NUM, threads = max_cpus\n"

@@ -951,16 +954,14 @@ static void display_help(int error)
 	       "-T TRACE --tracer=TRACER   set tracing function\n"
 	       "    configured tracers: %s\n"
 	       "-u       --unbuffered      force unbuffered output for live processing\n"
+	       "-U       --numa            Standard NUMA testing (similar to SMP option)\n"
+	       "                           thread data structures allocated from local node\n"
 	       "-v       --verbose         output values on stdout for statistics\n"
 	       "                           format: n:c:v n=tasknum c=count v=value in us\n"
-               "-w       --wakeup          task wakeup tracing (used with -b)\n"
-               "-W       --wakeuprt        rt task wakeup tracing (used with -b)\n"
-               "-y POLI  --policy=POLI     policy of realtime thread, POLI may be fifo(default) or rr\n"
-               "                           format: --policy=fifo(default) or --policy=rr\n"
-	       "-S       --smp             Standard SMP testing: options -a -t -n and\n"
-               "                           same priority of all threads\n"
-	       "-U       --numa            Standard NUMA testing (similar to SMP option)\n"
-               "                           thread data structures allocated from local node\n",
+	       "-w       --wakeup          task wakeup tracing (used with -b)\n"
+	       "-W       --wakeuprt        rt task wakeup tracing (used with -b)\n"
+	       "-y POLI  --policy=POLI     policy of realtime thread, POLI may be fifo(default) or rr\n"
+	       "                           format: --policy=fifo(default) or --policy=rr\n",
 	       tracers
 		);
 	if (error)

@@ -1044,48 +1045,51 @@ static void process_options (int argc, c
 
 	for (;;) {
  		int option_index = 0;
-		/** Options for getopt */
+		/*
+		 * Options for getopt
+		 * Ordered alphabetically by single letter name
+		 */
 		static struct option long_options[] = {
-			{"affinity", optional_argument, NULL, 'a'},
-			{"breaktrace", required_argument, NULL, 'b'},
-			{"preemptirqs", no_argument, NULL, 'B'},
-			{"clock", required_argument, NULL, 'c'},
-			{"context", no_argument, NULL, 'C'},
-			{"distance", required_argument, NULL, 'd'},
-			{"event", no_argument, NULL, 'E'},
-			{"ftrace", no_argument, NULL, 'f'},
-			{"histogram", required_argument, NULL, 'h'},
-			{"histofall", required_argument, NULL, 'H'},
-			{"interval", required_argument, NULL, 'i'},
-			{"irqsoff", no_argument, NULL, 'I'},
-			{"loops", required_argument, NULL, 'l'},
-			{"mlockall", no_argument, NULL, 'm' },
-			{"refresh_on_max", no_argument, NULL, 'M' },
-			{"nanosleep", no_argument, NULL, 'n'},
-			{"nsecs", no_argument, NULL, 'N'},
-			{"oscope", required_argument, NULL, 'o'},
-			{"priority", required_argument, NULL, 'p'},
-                        {"policy", required_argument, NULL, 'y'},
-			{"preemptoff", no_argument, NULL, 'P'},
-			{"quiet", no_argument, NULL, 'q'},
-			{"relative", no_argument, NULL, 'r'},
-			{"system", no_argument, NULL, 's'},
-			{"threads", optional_argument, NULL, 't'},
-			{"unbuffered", no_argument, NULL, 'u'},
-			{"verbose", no_argument, NULL, 'v'},
-			{"duration",required_argument, NULL, 'D'},
-                        {"wakeup", no_argument, NULL, 'w'},
-                        {"wakeuprt", no_argument, NULL, 'W'},
-			{"help", no_argument, NULL, '?'},
-			{"tracer", required_argument, NULL, 'T'},
-			{"traceopt", required_argument, NULL, 'O'},
-			{"smp", no_argument, NULL, 'S'},
-			{"numa", no_argument, NULL, 'U'},
-			{"latency", required_argument, NULL, 'e'},
-			{"priospread", no_argument, NULL, 'Q'},
+			{"affinity",         optional_argument, NULL, 'a'},
+			{"breaktrace",       required_argument, NULL, 'b'},
+			{"preemptirqs",      no_argument,       NULL, 'B'},
+			{"clock",            required_argument, NULL, 'c'},
+			{"context",          no_argument,       NULL, 'C'},
+			{"distance",         required_argument, NULL, 'd'},
+			{"duration",         required_argument, NULL, 'D'},
+			{"latency",          required_argument, NULL, 'e'},
+			{"event",            no_argument,       NULL, 'E'},
+			{"ftrace",           no_argument,       NULL, 'f'},
+			{"histogram",        required_argument, NULL, 'h'},
+			{"histofall",        required_argument, NULL, 'H'},
+			{"interval",         required_argument, NULL, 'i'},
+			{"irqsoff",          no_argument,       NULL, 'I'},
+			{"loops",            required_argument, NULL, 'l'},
+			{"mlockall",         no_argument,       NULL, 'm'},
+			{"refresh_on_max",   no_argument,       NULL, 'M'},
+			{"nanosleep",        no_argument,       NULL, 'n'},
+			{"nsecs",            no_argument,       NULL, 'N'},
+			{"oscope",           required_argument, NULL, 'o'},
+			{"traceopt",         required_argument, NULL, 'O'},
+			{"priority",         required_argument, NULL, 'p'},
+			{"preemptoff",       no_argument,       NULL, 'P'},
+			{"quiet",            no_argument,       NULL, 'q'},
+			{"priospread",       no_argument,       NULL, 'Q'},
+			{"relative",         no_argument,       NULL, 'r'},
+			{"system",           no_argument,       NULL, 's'},
+			{"smp",              no_argument,       NULL, 'S'},
+			{"threads",          optional_argument, NULL, 't'},
+			{"tracer",           required_argument, NULL, 'T'},
+			{"unbuffered",       no_argument,       NULL, 'u'},
+			{"numa",             no_argument,       NULL, 'U'},
+			{"verbose",          no_argument,       NULL, 'v'},
+			{"wakeup",           no_argument,       NULL, 'w'},
+			{"wakeuprt",         no_argument,       NULL, 'W'},
+			{"policy",           required_argument, NULL, 'y'},
+			{"help",             no_argument,       NULL, '?'},
 			{NULL, 0, NULL, 0}
 		};
-		int c = getopt_long(argc, argv, "a::b:Bc:Cd:Efh:H:i:Il:MnNo:O:p:PmqQrsSt::uUvD:wWT:y:e:",
+		int c = getopt_long(argc, argv, "a::b:Bc:Cd:D:e:Efh:H:i:Il:MnNo:O:p:PmqQrsSt::uUvD:wWT:y:",
 				    long_options, &option_index);
 		if (c == -1)
 			break;

@@ -1109,6 +1113,13 @@ static void process_options (int argc, c
 		case 'c': clocksel = atoi(optarg); break;
 		case 'C': tracetype = CTXTSWITCH; break;
 		case 'd': distance = atoi(optarg); break;
+		case 'D': duration = parse_time_string(optarg); break;
+		case 'e': /* power management latency target value */
+			  /* note: default is 0 (zero) */
+			latency_target_value = atoi(optarg);
+			if (latency_target_value < 0)
+				latency_target_value = 0;
+			break;
 		case 'E': enable_events = 1; break;
 		case 'f': tracetype = FUNCTION; ftrace = 1; break;
 		case 'H': histofall = 1; /* fall through */

@@ -1124,6 +1135,8 @@ static void process_options (int argc, c
 			}
 			break;
 		case 'l': max_cycles = atoi(optarg); break;
+		case 'm': lockall = 1; break;
+		case 'M': refresh_on_max = 1; break;
 		case 'n': use_nanosleep = MODE_CLOCK_NANOSLEEP; break;
 		case 'N': use_nsecs = 1; break;
 		case 'o': oscope_reduction = atoi(optarg); break;

@@ -1146,6 +1159,14 @@ static void process_options (int argc, c
 		case 'Q': priospread = 1; break;
 		case 'r': timermode = TIMER_RELTIME; break;
 		case 's': use_system = MODE_SYS_OFFSET; break;
+		case 'S':  /* SMP testing */
+			if (numa)
+				fatal("numa and smp options are mutually exclusive\n");
+			smp = 1;
+			num_threads = max_cpus;
+			setaffinity = AFFINITY_USEALL;
+			use_nanosleep = MODE_CLOCK_NANOSLEEP;
+			break;
 		case 't':
 			if (smp) {
 				warn("-t ignored due to --smp\n");

@@ -1163,22 +1184,6 @@ static void process_options (int argc, c
 			strncpy(tracer, optarg, sizeof(tracer)); 
 			break;
 		case 'u': setvbuf(stdout, NULL, _IONBF, 0); break;
-		case 'v': verbose = 1; break;
-		case 'm': lockall = 1; break;
-		case 'M': refresh_on_max = 1; break;
-		case 'D': duration = parse_time_string(optarg);
-			break;
-                case 'w': tracetype = WAKEUP; break;
-                case 'W': tracetype = WAKEUPRT; break;
-                case 'y': handlepolicy(optarg); break;
-		case 'S':  /* SMP testing */
-			if (numa)
-				fatal("numa and smp options are mutually exclusive\n");
-			smp = 1;
-			num_threads = max_cpus;
-			setaffinity = AFFINITY_USEALL;
-			use_nanosleep = MODE_CLOCK_NANOSLEEP;
-			break;
 		case 'U':  /* NUMA testing */
 			if (smp)
 				fatal("numa and smp options are mutually exclusive\n");

@@ -1194,12 +1199,10 @@ static void process_options (int argc, c
 			warn("ignoring --numa or -U\n");
 #endif
 			break;
-		case 'e': /* power management latency target value */
-			  /* note: default is 0 (zero) */
-			latency_target_value = atoi(optarg);