osnoise_hist.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
  4 */
  5
  6#define _GNU_SOURCE
  7#include <getopt.h>
  8#include <stdlib.h>
  9#include <string.h>
 10#include <signal.h>
 11#include <unistd.h>
 12#include <errno.h>
 13#include <stdio.h>
 14#include <time.h>
 15
 16#include "osnoise.h"
 17
 18struct osnoise_hist_cpu {
 19	int			*samples;
 20	int			count;
 21
 22	unsigned long long	min_sample;
 23	unsigned long long	sum_sample;
 24	unsigned long long	max_sample;
 25
 26};
 27
 28struct osnoise_hist_data {
 29	struct tracefs_hist	*trace_hist;
 30	struct osnoise_hist_cpu	*hist;
 31	int			entries;
 32	int			bucket_size;
 33	int			nr_cpus;
 34};
 35
 36/*
 37 * osnoise_free_histogram - free runtime data
 38 */
 39static void
 40osnoise_free_histogram(struct osnoise_hist_data *data)
 41{
 42	int cpu;
 43
 44	/* one histogram for IRQ and one for thread, per CPU */
 45	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
 46		if (data->hist[cpu].samples)
 47			free(data->hist[cpu].samples);
 48	}
 49
 50	/* one set of histograms per CPU */
 51	if (data->hist)
 52		free(data->hist);
 53
 54	free(data);
 55}
 56
 57static void osnoise_free_hist_tool(struct osnoise_tool *tool)
 58{
 59	osnoise_free_histogram(tool->data);
 60}
 61
 62/*
 63 * osnoise_alloc_histogram - alloc runtime data
 64 */
 65static struct osnoise_hist_data
 66*osnoise_alloc_histogram(int nr_cpus, int entries, int bucket_size)
 67{
 68	struct osnoise_hist_data *data;
 69	int cpu;
 70
 71	data = calloc(1, sizeof(*data));
 72	if (!data)
 73		return NULL;
 74
 75	data->entries = entries;
 76	data->bucket_size = bucket_size;
 77	data->nr_cpus = nr_cpus;
 78
 79	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
 80	if (!data->hist)
 81		goto cleanup;
 82
 83	for (cpu = 0; cpu < nr_cpus; cpu++) {
 84		data->hist[cpu].samples = calloc(1, sizeof(*data->hist->samples) * (entries + 1));
 85		if (!data->hist[cpu].samples)
 86			goto cleanup;
 87	}
 88
 89	/* set the min to max */
 90	for (cpu = 0; cpu < nr_cpus; cpu++)
 91		data->hist[cpu].min_sample = ~0;
 92
 93	return data;
 94
 95cleanup:
 96	osnoise_free_histogram(data);
 97	return NULL;
 98}
 99
100static void osnoise_hist_update_multiple(struct osnoise_tool *tool, int cpu,
101					 unsigned long long duration, int count)
102{
103	struct osnoise_params *params = to_osnoise_params(tool->params);
104	struct osnoise_hist_data *data = tool->data;
105	unsigned long long total_duration;
106	int entries = data->entries;
107	int bucket;
108	int *hist;
109
110	if (params->common.output_divisor)
111		duration = duration / params->common.output_divisor;
112
113	bucket = duration / data->bucket_size;
114
115	total_duration = duration * count;
116
117	hist = data->hist[cpu].samples;
118	data->hist[cpu].count += count;
119	update_min(&data->hist[cpu].min_sample, &duration);
120	update_sum(&data->hist[cpu].sum_sample, &total_duration);
121	update_max(&data->hist[cpu].max_sample, &duration);
122
123	if (bucket < entries)
124		hist[bucket] += count;
125	else
126		hist[entries] += count;
127}
128
129/*
130 * osnoise_destroy_trace_hist - disable events used to collect histogram
131 */
132static void osnoise_destroy_trace_hist(struct osnoise_tool *tool)
133{
134	struct osnoise_hist_data *data = tool->data;
135
136	tracefs_hist_pause(tool->trace.inst, data->trace_hist);
137	tracefs_hist_destroy(tool->trace.inst, data->trace_hist);
138}
139
140/*
141 * osnoise_init_trace_hist - enable events used to collect histogram
142 */
143static int osnoise_init_trace_hist(struct osnoise_tool *tool)
144{
145	struct osnoise_params *params = to_osnoise_params(tool->params);
146	struct osnoise_hist_data *data = tool->data;
147	int bucket_size;
148	char buff[128];
149	int retval = 0;
150
151	/*
152	 * Set the size of the bucket.
153	 */
154	bucket_size = params->common.output_divisor * params->common.hist.bucket_size;
155	snprintf(buff, sizeof(buff), "duration.buckets=%d", bucket_size);
156
157	data->trace_hist = tracefs_hist_alloc(tool->trace.tep, "osnoise", "sample_threshold",
158			buff, TRACEFS_HIST_KEY_NORMAL);
159	if (!data->trace_hist)
160		return 1;
161
162	retval = tracefs_hist_add_key(data->trace_hist, "cpu", 0);
163	if (retval)
164		goto out_err;
165
166	retval = tracefs_hist_start(tool->trace.inst, data->trace_hist);
167	if (retval)
168		goto out_err;
169
170	return 0;
171
172out_err:
173	osnoise_destroy_trace_hist(tool);
174	return 1;
175}
176
177/*
178 * osnoise_read_trace_hist - parse histogram file and file osnoise histogram
179 */
180static void osnoise_read_trace_hist(struct osnoise_tool *tool)
181{
182	struct osnoise_hist_data *data = tool->data;
183	long long cpu, counter, duration;
184	char *content, *position;
185
186	tracefs_hist_pause(tool->trace.inst, data->trace_hist);
187
188	content = tracefs_event_file_read(tool->trace.inst, "osnoise",
189					  "sample_threshold",
190					  "hist", NULL);
191	if (!content)
192		return;
193
194	position = content;
195	while (true) {
196		position = strstr(position, "duration: ~");
197		if (!position)
198			break;
199		position += strlen("duration: ~");
200		duration = get_llong_from_str(position);
201		if (duration == -1)
202			err_msg("error reading duration from histogram\n");
203
204		position = strstr(position, "cpu:");
205		if (!position)
206			break;
207		position += strlen("cpu: ");
208		cpu = get_llong_from_str(position);
209		if (cpu == -1)
210			err_msg("error reading cpu from histogram\n");
211
212		position = strstr(position, "hitcount:");
213		if (!position)
214			break;
215		position += strlen("hitcount: ");
216		counter = get_llong_from_str(position);
217		if (counter == -1)
218			err_msg("error reading counter from histogram\n");
219
220		osnoise_hist_update_multiple(tool, cpu, duration, counter);
221	}
222	free(content);
223}
224
225/*
226 * osnoise_hist_header - print the header of the tracer to the output
227 */
228static void osnoise_hist_header(struct osnoise_tool *tool)
229{
230	struct osnoise_params *params = to_osnoise_params(tool->params);
231	struct osnoise_hist_data *data = tool->data;
232	struct trace_seq *s = tool->trace.seq;
233	char duration[26];
234	int cpu;
235
236	if (params->common.hist.no_header)
237		return;
238
239	get_duration(tool->start_time, duration, sizeof(duration));
240	trace_seq_printf(s, "# RTLA osnoise histogram\n");
241	trace_seq_printf(s, "# Time unit is %s (%s)\n",
242			params->common.output_divisor == 1 ? "nanoseconds" : "microseconds",
243			params->common.output_divisor == 1 ? "ns" : "us");
244
245	trace_seq_printf(s, "# Duration: %s\n", duration);
246
247	if (!params->common.hist.no_index)
248		trace_seq_printf(s, "Index");
249
250	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
251
252		if (!data->hist[cpu].count)
253			continue;
254
255		trace_seq_printf(s, "   CPU-%03d", cpu);
256	}
257	trace_seq_printf(s, "\n");
258
259	trace_seq_do_printf(s);
260	trace_seq_reset(s);
261}
262
263/*
264 * osnoise_print_summary - print the summary of the hist data to the output
265 */
266static void
267osnoise_print_summary(struct osnoise_params *params,
268		       struct trace_instance *trace,
269		       struct osnoise_hist_data *data)
270{
271	int cpu;
272
273	if (params->common.hist.no_summary)
274		return;
275
276	if (!params->common.hist.no_index)
277		trace_seq_printf(trace->seq, "count:");
278
279	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
280
281		if (!data->hist[cpu].count)
282			continue;
283
284		trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].count);
285	}
286	trace_seq_printf(trace->seq, "\n");
287
288	if (!params->common.hist.no_index)
289		trace_seq_printf(trace->seq, "min:  ");
290
291	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
292
293		if (!data->hist[cpu].count)
294			continue;
295
296		trace_seq_printf(trace->seq, "%9llu ",	data->hist[cpu].min_sample);
297
298	}
299	trace_seq_printf(trace->seq, "\n");
300
301	if (!params->common.hist.no_index)
302		trace_seq_printf(trace->seq, "avg:  ");
303
304	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
305
306		if (!data->hist[cpu].count)
307			continue;
308
309		if (data->hist[cpu].count)
310			trace_seq_printf(trace->seq, "%9.2f ",
311				((double) data->hist[cpu].sum_sample) / data->hist[cpu].count);
312		else
313			trace_seq_printf(trace->seq, "        - ");
314	}
315	trace_seq_printf(trace->seq, "\n");
316
317	if (!params->common.hist.no_index)
318		trace_seq_printf(trace->seq, "max:  ");
319
320	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
321
322		if (!data->hist[cpu].count)
323			continue;
324
325		trace_seq_printf(trace->seq, "%9llu ", data->hist[cpu].max_sample);
326
327	}
328	trace_seq_printf(trace->seq, "\n");
329	trace_seq_do_printf(trace->seq);
330	trace_seq_reset(trace->seq);
331}
332
333/*
334 * osnoise_print_stats - print data for all CPUs
335 */
336static void
337osnoise_print_stats(struct osnoise_tool *tool)
338{
339	struct osnoise_params *params = to_osnoise_params(tool->params);
340	struct osnoise_hist_data *data = tool->data;
341	struct trace_instance *trace = &tool->trace;
342	int has_samples = 0;
343	int bucket, cpu;
344	int total;
345
346	osnoise_hist_header(tool);
347
348	for (bucket = 0; bucket < data->entries; bucket++) {
349		total = 0;
350
351		if (!params->common.hist.no_index)
352			trace_seq_printf(trace->seq, "%-6d",
353					 bucket * data->bucket_size);
354
355		for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
356
357			if (!data->hist[cpu].count)
358				continue;
359
360			total += data->hist[cpu].samples[bucket];
361			trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].samples[bucket]);
362		}
363
364		if (total == 0 && !params->common.hist.with_zeros) {
365			trace_seq_reset(trace->seq);
366			continue;
367		}
368
369		/* There are samples above the threshold */
370		has_samples = 1;
371		trace_seq_printf(trace->seq, "\n");
372		trace_seq_do_printf(trace->seq);
373		trace_seq_reset(trace->seq);
374	}
375
376	/*
377	 * If no samples were recorded, skip calculations, print zeroed statistics
378	 * and return.
379	 */
380	if (!has_samples) {
381		trace_seq_reset(trace->seq);
382		trace_seq_printf(trace->seq, "over: 0\ncount: 0\nmin: 0\navg: 0\nmax: 0\n");
383		trace_seq_do_printf(trace->seq);
384		trace_seq_reset(trace->seq);
385		return;
386	}
387
388	if (!params->common.hist.no_index)
389		trace_seq_printf(trace->seq, "over: ");
390
391	for_each_monitored_cpu(cpu, data->nr_cpus, &params->common) {
392
393		if (!data->hist[cpu].count)
394			continue;
395
396		trace_seq_printf(trace->seq, "%9d ",
397				 data->hist[cpu].samples[data->entries]);
398	}
399	trace_seq_printf(trace->seq, "\n");
400	trace_seq_do_printf(trace->seq);
401	trace_seq_reset(trace->seq);
402
403	osnoise_print_summary(params, trace, data);
404	osnoise_report_missed_events(tool);
405}
406
407/*
408 * osnoise_hist_usage - prints osnoise hist usage message
409 */
410static void osnoise_hist_usage(void)
411{
412	int i;
413
414	static const char * const msg[] = {
415		"",
416		"  usage: rtla osnoise hist [-h] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
417		"	  [-T us] [-t [file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
418		"	  [-c cpu-list] [-H cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] \\",
419		"	  [--no-index] [--with-zeros] [-C [cgroup_name]] [--warm-up]",
420		"",
421		"	  -h/--help: print this menu",
422		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
423		"	  -p/--period us: osnoise period in us",
424		"	  -r/--runtime us: osnoise runtime in us",
425		"	  -s/--stop us: stop trace if a single sample is higher than the argument in us",
426		"	  -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
427		"	  -T/--threshold us: the minimum delta to be considered a noise",
428		"	  -c/--cpus cpu-list: list of cpus to run osnoise threads",
429		"	  -H/--house-keeping cpus: run rtla control threads only on the given cpus",
430		"	  -C/--cgroup [cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
431		"	  -d/--duration time[s|m|h|d]: duration of the session",
432		"	  -D/--debug: print debug info",
433		"	  -t/--trace [file]: save the stopped trace to [file|osnoise_trace.txt]",
434		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
435		"	     --filter <filter>: enable a trace event filter to the previous -e event",
436		"	     --trigger <trigger>: enable a trace event trigger to the previous -e event",
437		"	  -b/--bucket-size N: set the histogram bucket size (default 1)",
438		"	  -E/--entries N: set the number of entries of the histogram (default 256)",
439		"	     --no-header: do not print header",
440		"	     --no-summary: do not print summary",
441		"	     --no-index: do not print index",
442		"	     --with-zeros: print zero only entries",
443		"	  -P/--priority o:prio|r:prio|f:prio|d:runtime:period: set scheduling parameters",
444		"		o:prio - use SCHED_OTHER with prio",
445		"		r:prio - use SCHED_RR with prio",
446		"		f:prio - use SCHED_FIFO with prio",
447		"		d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
448		"						       in nanoseconds",
449		"	     --warm-up: let the workload run for s seconds before collecting data",
450		"	     --trace-buffer-size kB: set the per-cpu trace buffer size in kB",
451		"	     --on-threshold <action>: define action to be executed at stop-total threshold, multiple are allowed",
452		"	     --on-end <action>: define action to be executed at measurement end, multiple are allowed",
453		NULL,
454	};
455
456	fprintf(stderr, "rtla osnoise hist: a per-cpu histogram of the OS noise (version %s)\n",
457			VERSION);
458
459	for (i = 0; msg[i]; i++)
460		fprintf(stderr, "%s\n", msg[i]);
461
462	exit(EXIT_SUCCESS);
463}
464
465/*
466 * osnoise_hist_parse_args - allocs, parse and fill the cmd line parameters
467 */
468static struct common_params
469*osnoise_hist_parse_args(int argc, char *argv[])
470{
471	struct osnoise_params *params;
472	struct trace_events *tevent;
473	int retval;
474	int c;
475	char *trace_output = NULL;
476
477	params = calloc(1, sizeof(*params));
478	if (!params)
479		exit(1);
480
481	actions_init(&params->common.threshold_actions);
482	actions_init(&params->common.end_actions);
483
484	/* display data in microseconds */
485	params->common.output_divisor = 1000;
486	params->common.hist.bucket_size = 1;
487	params->common.hist.entries = 256;
488
489	while (1) {
490		static struct option long_options[] = {
491			{"auto",		required_argument,	0, 'a'},
492			{"bucket-size",		required_argument,	0, 'b'},
493			{"entries",		required_argument,	0, 'E'},
494			{"cpus",		required_argument,	0, 'c'},
495			{"cgroup",		optional_argument,	0, 'C'},
496			{"debug",		no_argument,		0, 'D'},
497			{"duration",		required_argument,	0, 'd'},
498			{"house-keeping",	required_argument,		0, 'H'},
499			{"help",		no_argument,		0, 'h'},
500			{"period",		required_argument,	0, 'p'},
501			{"priority",		required_argument,	0, 'P'},
502			{"runtime",		required_argument,	0, 'r'},
503			{"stop",		required_argument,	0, 's'},
504			{"stop-total",		required_argument,	0, 'S'},
505			{"trace",		optional_argument,	0, 't'},
506			{"event",		required_argument,	0, 'e'},
507			{"threshold",		required_argument,	0, 'T'},
508			{"no-header",		no_argument,		0, '0'},
509			{"no-summary",		no_argument,		0, '1'},
510			{"no-index",		no_argument,		0, '2'},
511			{"with-zeros",		no_argument,		0, '3'},
512			{"trigger",		required_argument,	0, '4'},
513			{"filter",		required_argument,	0, '5'},
514			{"warm-up",		required_argument,	0, '6'},
515			{"trace-buffer-size",	required_argument,	0, '7'},
516			{"on-threshold",	required_argument,	0, '8'},
517			{"on-end",		required_argument,	0, '9'},
518			{0, 0, 0, 0}
519		};
520
521		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:p:P:r:s:S:t::T:01234:5:6:7:",
522				 long_options, NULL);
523
524		/* detect the end of the options. */
525		if (c == -1)
526			break;
527
528		switch (c) {
529		case 'a':
530			/* set sample stop to auto_thresh */
531			params->common.stop_us = get_llong_from_str(optarg);
532
533			/* set sample threshold to 1 */
534			params->threshold = 1;
535
536			/* set trace */
537			if (!trace_output)
538				trace_output = "osnoise_trace.txt";
539
540			break;
541		case 'b':
542			params->common.hist.bucket_size = get_llong_from_str(optarg);
543			if (params->common.hist.bucket_size == 0 ||
544			    params->common.hist.bucket_size >= 1000000)
545				fatal("Bucket size needs to be > 0 and <= 1000000");
546			break;
547		case 'c':
548			retval = parse_cpu_set(optarg, &params->common.monitored_cpus);
549			if (retval)
550				fatal("Invalid -c cpu list");
551			params->common.cpus = optarg;
552			break;
553		case 'C':
554			params->common.cgroup = 1;
555			params->common.cgroup_name = parse_optional_arg(argc, argv);
556			break;
557		case 'D':
558			config_debug = 1;
559			break;
560		case 'd':
561			params->common.duration = parse_seconds_duration(optarg);
562			if (!params->common.duration)
563				fatal("Invalid -D duration");
564			break;
565		case 'e':
566			tevent = trace_event_alloc(optarg);
567			if (!tevent)
568				fatal("Error alloc trace event");
569
570			if (params->common.events)
571				tevent->next = params->common.events;
572
573			params->common.events = tevent;
574			break;
575		case 'E':
576			params->common.hist.entries = get_llong_from_str(optarg);
577			if (params->common.hist.entries < 10 ||
578			    params->common.hist.entries > 9999999)
579				fatal("Entries must be > 10 and < 9999999");
580			break;
581		case 'h':
582		case '?':
583			osnoise_hist_usage();
584			break;
585		case 'H':
586			params->common.hk_cpus = 1;
587			retval = parse_cpu_set(optarg, &params->common.hk_cpu_set);
588			if (retval)
589				fatal("Error parsing house keeping CPUs");
590			break;
591		case 'p':
592			params->period = get_llong_from_str(optarg);
593			if (params->period > 10000000)
594				fatal("Period longer than 10 s");
595			break;
596		case 'P':
597			retval = parse_prio(optarg, &params->common.sched_param);
598			if (retval == -1)
599				fatal("Invalid -P priority");
600			params->common.set_sched = 1;
601			break;
602		case 'r':
603			params->runtime = get_llong_from_str(optarg);
604			if (params->runtime < 100)
605				fatal("Runtime shorter than 100 us");
606			break;
607		case 's':
608			params->common.stop_us = get_llong_from_str(optarg);
609			break;
610		case 'S':
611			params->common.stop_total_us = get_llong_from_str(optarg);
612			break;
613		case 'T':
614			params->threshold = get_llong_from_str(optarg);
615			break;
616		case 't':
617			trace_output = parse_optional_arg(argc, argv);
618			if (!trace_output)
619				trace_output = "osnoise_trace.txt";
620			break;
621		case '0': /* no header */
622			params->common.hist.no_header = 1;
623			break;
624		case '1': /* no summary */
625			params->common.hist.no_summary = 1;
626			break;
627		case '2': /* no index */
628			params->common.hist.no_index = 1;
629			break;
630		case '3': /* with zeros */
631			params->common.hist.with_zeros = 1;
632			break;
633		case '4': /* trigger */
634			if (params->common.events) {
635				retval = trace_event_add_trigger(params->common.events, optarg);
636				if (retval)
637					fatal("Error adding trigger %s", optarg);
638			} else {
639				fatal("--trigger requires a previous -e");
640			}
641			break;
642		case '5': /* filter */
643			if (params->common.events) {
644				retval = trace_event_add_filter(params->common.events, optarg);
645				if (retval)
646					fatal("Error adding filter %s", optarg);
647			} else {
648				fatal("--filter requires a previous -e");
649			}
650			break;
651		case '6':
652			params->common.warmup = get_llong_from_str(optarg);
653			break;
654		case '7':
655			params->common.buffer_size = get_llong_from_str(optarg);
656			break;
657		case '8':
658			retval = actions_parse(&params->common.threshold_actions, optarg,
659					       "osnoise_trace.txt");
660			if (retval)
661				fatal("Invalid action %s", optarg);
662			break;
663		case '9':
664			retval = actions_parse(&params->common.end_actions, optarg,
665					       "osnoise_trace.txt");
666			if (retval)
667				fatal("Invalid action %s", optarg);
668			break;
669		default:
670			fatal("Invalid option");
671		}
672	}
673
674	if (trace_output)
675		actions_add_trace_output(&params->common.threshold_actions, trace_output);
676
677	if (geteuid())
678		fatal("rtla needs root permission");
679
680	if (params->common.hist.no_index && !params->common.hist.with_zeros)
681		fatal("no-index set and with-zeros not set - it does not make sense");
682
683	return &params->common;
684}
685
686/*
687 * osnoise_hist_apply_config - apply the hist configs to the initialized tool
688 */
689static int
690osnoise_hist_apply_config(struct osnoise_tool *tool)
691{
692	return osnoise_apply_config(tool, to_osnoise_params(tool->params));
693}
694
695/*
696 * osnoise_init_hist - initialize a osnoise hist tool with parameters
697 */
698static struct osnoise_tool
699*osnoise_init_hist(struct common_params *params)
700{
701	struct osnoise_tool *tool;
702	int nr_cpus;
703
704	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
705
706	tool = osnoise_init_tool("osnoise_hist");
707	if (!tool)
708		return NULL;
709
710	tool->data = osnoise_alloc_histogram(nr_cpus, params->hist.entries,
711					     params->hist.bucket_size);
712	if (!tool->data)
713		goto out_err;
714
715	return tool;
716
717out_err:
718	osnoise_destroy_tool(tool);
719	return NULL;
720}
721
722static int osnoise_hist_enable(struct osnoise_tool *tool)
723{
724	int retval;
725
726	retval = osnoise_init_trace_hist(tool);
727	if (retval)
728		return retval;
729
730	return osnoise_enable(tool);
731}
732
733static int osnoise_hist_main_loop(struct osnoise_tool *tool)
734{
735	int retval;
736
737	retval = hist_main_loop(tool);
738	osnoise_read_trace_hist(tool);
739
740	return retval;
741}
742
743struct tool_ops osnoise_hist_ops = {
744	.tracer = "osnoise",
745	.comm_prefix = "osnoise/",
746	.parse_args = osnoise_hist_parse_args,
747	.init_tool = osnoise_init_hist,
748	.apply_config = osnoise_hist_apply_config,
749	.enable = osnoise_hist_enable,
750	.main = osnoise_hist_main_loop,
751	.print_stats = osnoise_print_stats,
752	.free = osnoise_free_hist_tool,
753};