stat: make latency buckets configurable

Allow the user to set how many latency buckets there are at the finest
granularity (when unset the default is 10). The number of larger granularity
buckets is calculated as the finest + 2.

Signed-off-by: Tokunori Ikegami <[email protected]>

Author: ikegami-t

HOWTO

@@ -299,6 +299,10 @@ Command line options
 	Use the directory specified by `path` for generated state files instead
 	of the current working directory.
 
+.. option:: --latency-stats=nr
+
+	Change default latency stats number. The default buckets number is 10.
+
 Any parameters following the options will be assumed to be job files, unless
 they match a job file parameter. Multiple job files can be listed and each job
 file will be regarded as a separate group. Fio will :option:`stonewall`
@@ -4045,13 +4049,20 @@ field was introduced or whether it's specific to some terse version):
 
         <=1, 2, 4, 8, 16, 32, >=64
 
+    I/O latencies nanoseconds::
+
+        <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+        The number of buckets may vary.
+
     I/O latencies microseconds::
 
         <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+        The number of buckets may vary.
 
     I/O latencies milliseconds::
 
         <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+        The number of buckets may vary.
 
     Disk utilization [v3]::
 
@@ -4084,7 +4095,7 @@ minimal output v3, separated by semicolons::
 In client/server mode terse output differs from what appears when jobs are run
 locally. Disk utilization data is omitted from the standard terse output and
 for v3 and later appears on its own separate line at the end of each terse
-reporting cycle.
+reporting cycle. The number of buckets may vary.
 
 
 JSON output

client.c

@@ -2150,6 +2150,8 @@ int fio_handle_clients(struct client_ops *ops)
 
 	fio_client_json_fini();
 
+	stat_free_lat(&client_ts);
+
 	free(pfds);
 	return retval || error_clients;
 }

debug.h

@@ -23,6 +23,7 @@ enum {
 	FD_STEADYSTATE,
 	FD_HELPERTHREAD,
 	FD_ZBD,
+	FD_STAT,
 	FD_DEBUG_MAX,
 };
 

fio.1

@@ -176,6 +176,9 @@ Set this \fIcommand\fR as remote trigger.
 .BI \-\-aux\-path \fR=\fPpath
 Use the directory specified by \fIpath\fP for generated state files instead
 of the current working directory.
+.TP
+.BI \-\-latency\-stats \fR=\fPnr
+Change default latency stats number. The default buckets number is 10.
 .SH "JOB FILE FORMAT"
 Any parameters following the options will be assumed to be job files, unless
 they match a job file parameter. Multiple job files can be listed and each job
@@ -3748,11 +3751,22 @@ I/O depths:
 .RS
 .P
 .B
+I/O latencies nanoseconds:
+.RE
+.P
+.nf
+			<=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+			The number of buckets may vary.
+.fi
+.RS
+.P
+.B
 I/O latencies microseconds:
 .RE
 .P
 .nf
 			<=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+			The number of buckets may vary.
 .fi
 .RS
 .P
@@ -3762,6 +3776,7 @@ I/O latencies milliseconds:
 .P
 .nf
 			<=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+			The number of buckets may vary.
 .fi
 .RS
 .P
@@ -3813,7 +3828,7 @@ minimal output v3, separated by semicolons:
 In client/server mode terse output differs from what appears when jobs are run
 locally. Disk utilization data is omitted from the standard terse output and
 for v3 and later appears on its own separate line at the end of each terse
-reporting cycle.
+reporting cycle. The number of buckets may vary.
 .SH JSON OUTPUT
 The \fBjson\fR output format is intended to be both human readable and convenient
 for automated parsing. For the most part its sections mirror those of the

init.c

@@ -293,6 +293,11 @@ static struct option l_opts[FIO_NR_OPTIONS] = {
 		.has_arg	= no_argument,
 		.val		= 'A' | FIO_CLIENT_FLAG,
 	},
+	{
+		.name		= (char *) "latency-stats",
+		.has_arg	= required_argument,
+		.val		= 'n' | FIO_CLIENT_FLAG,
+	},
 	{
 		.name		= NULL,
 	},
@@ -537,6 +542,8 @@ static void put_job(struct thread_data *td)
 	if (td->o.name)
 		free(td->o.name);
 
+	stat_free_lat(&td->ts);
+
 	memset(td, 0, sizeof(*td));
 	segments[cur_segment].nr_threads--;
 	thread_number--;
@@ -1532,6 +1539,7 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num,
 		td->ts.clat_low_prio_stat[i].min_val = ULONG_MAX;
 	}
 	td->ts.sync_stat.min_val = ULONG_MAX;
+	stat_alloc_lat(&td->ts);
 	td->ddir_seq_nr = o->ddir_seq_nr;
 
 	if ((o->stonewall || o->new_group) && prev_group_jobs) {
@@ -2241,6 +2249,7 @@ static void usage(const char *name)
 	printf("  --trigger=cmd\t\tSet this command as local trigger\n");
 	printf("  --trigger-remote=cmd\tSet this command as remote trigger\n");
 	printf("  --aux-path=path\tUse this path for fio state generated files\n");
+	printf("  --latency-stats=nr\tChange default latency stats number\n");
 	printf("\nFio was written by Jens Axboe <[email protected]>\n");
 }
 
@@ -2322,6 +2331,10 @@ const struct debug_level debug_levels[] = {
 	  .help = "Zoned Block Device logging",
 	  .shift = FD_ZBD,
 	},
+	{ .name = "stat",
+	  .help = "Statisitics logging",
+	  .shift = FD_STAT,
+	},
 	{ .name = NULL, },
 };
 
@@ -2906,11 +2919,17 @@ int parse_cmd_line(int argc, char *argv[], int client_type)
 			}
 			trigger_timeout /= 1000000;
 			break;
-
 		case 'A':
 			did_arg = true;
 			merge_blktrace_only = true;
 			break;
+		case 'n':
+			if (!stat_set_lat(atoi(optarg))) {
+				log_err("fio: bad latency stats number\n");
+				exit_val = 1;
+				do_exit++;
+			}
+			break;
 		case '?':
 			log_err("%s: unrecognized option '%s'\n", argv[0],
 							argv[optind - 1]);

io_u.c

@@ -1045,129 +1045,44 @@ void io_u_mark_depth(struct thread_data *td, unsigned int nr)
 
 static void io_u_mark_lat_nsec(struct thread_data *td, unsigned long long nsec)
 {
-	int idx = 0;
+	int idx;
 
 	assert(nsec < 1000);
 
-	switch (nsec) {
-	case 750 ... 999:
-		idx = 9;
-		break;
-	case 500 ... 749:
-		idx = 8;
-		break;
-	case 250 ... 499:
-		idx = 7;
-		break;
-	case 100 ... 249:
-		idx = 6;
-		break;
-	case 50 ... 99:
-		idx = 5;
-		break;
-	case 20 ... 49:
-		idx = 4;
-		break;
-	case 10 ... 19:
-		idx = 3;
-		break;
-	case 4 ... 9:
-		idx = 2;
-		break;
-	case 2 ... 3:
-		idx = 1;
-		fallthrough;
-	case 0 ... 1:
-		break;
-	}
+	idx = stat_get_lat_idx(nsec);
 
 	assert(idx < FIO_IO_U_LAT_N_NR);
 	td->ts.io_u_lat_n[idx]++;
 }
 
 static void io_u_mark_lat_usec(struct thread_data *td, unsigned long long usec)
 {
-	int idx = 0;
+	int idx;
 
 	assert(usec < 1000 && usec >= 1);
 
-	switch (usec) {
-	case 750 ... 999:
-		idx = 9;
-		break;
-	case 500 ... 749:
-		idx = 8;
-		break;
-	case 250 ... 499:
-		idx = 7;
-		break;
-	case 100 ... 249:
-		idx = 6;
-		break;
-	case 50 ... 99:
-		idx = 5;
-		break;
-	case 20 ... 49:
-		idx = 4;
-		break;
-	case 10 ... 19:
-		idx = 3;
-		break;
-	case 4 ... 9:
-		idx = 2;
-		break;
-	case 2 ... 3:
-		idx = 1;
-		fallthrough;
-	case 0 ... 1:
-		break;
-	}
+	idx = stat_get_lat_idx(usec);
 
 	assert(idx < FIO_IO_U_LAT_U_NR);
 	td->ts.io_u_lat_u[idx]++;
 }
 
 static void io_u_mark_lat_msec(struct thread_data *td, unsigned long long msec)
 {
-	int idx = 0;
+	int idx;
+	int nr = stat_get_lat_m_nr();
 
 	assert(msec >= 1);
 
 	switch (msec) {
 	default:
-		idx = 11;
+		idx = nr - 1;
 		break;
 	case 1000 ... 1999:
-		idx = 10;
-		break;
-	case 750 ... 999:
-		idx = 9;
-		break;
-	case 500 ... 749:
-		idx = 8;
+		idx = nr - 2;
 		break;
-	case 250 ... 499:
-		idx = 7;
-		break;
-	case 100 ... 249:
-		idx = 6;
-		break;
-	case 50 ... 99:
-		idx = 5;
-		break;
-	case 20 ... 49:
-		idx = 4;
-		break;
-	case 10 ... 19:
-		idx = 3;
-		break;
-	case 4 ... 9:
-		idx = 2;
-		break;
-	case 2 ... 3:
-		idx = 1;
-		fallthrough;
-	case 0 ... 1:
+	case 1 ... 999:
+		idx = stat_get_lat_idx(msec);
 		break;
 	}
 

server.h

@@ -48,7 +48,7 @@ struct fio_net_cmd_reply {
 };
 
 enum {
-	FIO_SERVER_VER			= 91,
+	FIO_SERVER_VER			= 92,
 
 	FIO_SERVER_MAX_FRAGMENT_PDU	= 1024,
 	FIO_SERVER_MAX_CMD_MB		= 2048,