Commit 829a6c0b authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt

rtla/osnoise: Add the hist mode

The rtla osnoise hist tool collects all osnoise:sample_threshold
occurrence in a histogram, displaying the results in a user-friendly
way. The tool also allows many configurations of the osnoise tracer
and the collection of the tracer output.

Here is one example of the rtla osnoise hist tool output:
  ---------- %< ----------
 [root@f34 ~]# rtla osnoise hist --bucket-size 10 --entries 100 -c 0-8 -d 1M -r 9000 -P F:1
 # RTLA osnoise histogram
 # Time unit is microseconds (us)
 # Duration:   0 00:01:00
 Index   CPU-000   CPU-001   CPU-002   CPU-003   CPU-004   CPU-005   CPU-006   CPU-007   CPU-008
 0           430       434       352       455       440       463       467       436       484
 10           88        88        92       141       120       100       126       166       100
 20           19         7        12        22         8         8        13        13        16
 30            6         0         2         0         1         2         2         1         0
 50            0         0         0         0         0         0         1         0         0
 over:         0         0         0         0         0         0         0         0         0
 count:      543       529       458       618       569       573       609       616       600
 min:          0         0         0         0         0         0         0         0         0
 avg:          0         0         0         0         0         0         0         0         0
 max:         30        20        30        20        30        30        50        30        20
  ---------- >% ----------

Running
 - rtla osnoise hist --help

provides information about the available options.

Link: https://lkml.kernel.org/r/c68060544de89b8b62510ed91c7369f162eb465b.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 1eceb2fc
......@@ -829,6 +829,7 @@ static void osnoise_usage(void)
"",
" modes:",
" top - prints the summary from osnoise tracer",
" hist - prints a histogram of osnoise samples",
"",
"if no MODE is given, the top mode is called, passing the arguments",
NULL,
......@@ -863,6 +864,9 @@ int osnoise_main(int argc, char *argv[])
} else if (strcmp(argv[1], "top") == 0) {
osnoise_top_main(argc-1, &argv[1]);
exit(0);
} else if (strcmp(argv[1], "hist") == 0) {
osnoise_hist_main(argc-1, &argv[1]);
exit(0);
}
usage:
......
......@@ -86,5 +86,6 @@ void osnoise_destroy_tool(struct osnoise_tool *top);
struct osnoise_tool *osnoise_init_tool(char *tool_name);
struct osnoise_tool *osnoise_init_trace_tool(char *tracer);
int osnoise_hist_main(int argc, char *argv[]);
int osnoise_top_main(int argc, char **argv);
int osnoise_main(int argc, char **argv);
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include "utils.h"
#include "osnoise.h"
struct osnoise_hist_params {
char *cpus;
char *monitored_cpus;
char *trace_output;
unsigned long long runtime;
unsigned long long period;
long long stop_us;
long long stop_total_us;
int sleep_time;
int duration;
int set_sched;
int output_divisor;
struct sched_attr sched_param;
char no_header;
char no_summary;
char no_index;
char with_zeros;
int bucket_size;
int entries;
};
struct osnoise_hist_cpu {
int *samples;
int count;
unsigned long long min_sample;
unsigned long long sum_sample;
unsigned long long max_sample;
};
struct osnoise_hist_data {
struct tracefs_hist *trace_hist;
struct osnoise_hist_cpu *hist;
int entries;
int bucket_size;
int nr_cpus;
};
/*
* osnoise_free_histogram - free runtime data
*/
static void
osnoise_free_histogram(struct osnoise_hist_data *data)
{
int cpu;
/* one histogram for IRQ and one for thread, per CPU */
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (data->hist[cpu].samples)
free(data->hist[cpu].samples);
}
/* one set of histograms per CPU */
if (data->hist)
free(data->hist);
free(data);
}
/*
* osnoise_alloc_histogram - alloc runtime data
*/
static struct osnoise_hist_data
*osnoise_alloc_histogram(int nr_cpus, int entries, int bucket_size)
{
struct osnoise_hist_data *data;
int cpu;
data = calloc(1, sizeof(*data));
if (!data)
return NULL;
data->entries = entries;
data->bucket_size = bucket_size;
data->nr_cpus = nr_cpus;
data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
if (!data->hist)
goto cleanup;
for (cpu = 0; cpu < nr_cpus; cpu++) {
data->hist[cpu].samples = calloc(1, sizeof(*data->hist->samples) * (entries + 1));
if (!data->hist[cpu].samples)
goto cleanup;
}
/* set the min to max */
for (cpu = 0; cpu < nr_cpus; cpu++)
data->hist[cpu].min_sample = ~0;
return data;
cleanup:
osnoise_free_histogram(data);
return NULL;
}
static void osnoise_hist_update_multiple(struct osnoise_tool *tool, int cpu,
unsigned long long duration, int count)
{
struct osnoise_hist_params *params = tool->params;
struct osnoise_hist_data *data = tool->data;
int entries = data->entries;
int bucket;
int *hist;
if (params->output_divisor)
duration = duration / params->output_divisor;
if (data->bucket_size)
bucket = duration / data->bucket_size;
hist = data->hist[cpu].samples;
data->hist[cpu].count += count;
update_min(&data->hist[cpu].min_sample, &duration);
update_sum(&data->hist[cpu].sum_sample, &duration);
update_max(&data->hist[cpu].max_sample, &duration);
if (bucket < entries)
hist[bucket] += count;
else
hist[entries] += count;
}
/*
* osnoise_destroy_trace_hist - disable events used to collect histogram
*/
static void osnoise_destroy_trace_hist(struct osnoise_tool *tool)
{
struct osnoise_hist_data *data = tool->data;
tracefs_hist_pause(tool->trace.inst, data->trace_hist);
tracefs_hist_destroy(tool->trace.inst, data->trace_hist);
}
/*
* osnoise_init_trace_hist - enable events used to collect histogram
*/
static int osnoise_init_trace_hist(struct osnoise_tool *tool)
{
struct osnoise_hist_params *params = tool->params;
struct osnoise_hist_data *data = tool->data;
int bucket_size;
char buff[128];
int retval = 0;
/*
* Set the size of the bucket.
*/
bucket_size = params->output_divisor * params->bucket_size;
snprintf(buff, sizeof(buff), "duration.buckets=%d", bucket_size);
data->trace_hist = tracefs_hist_alloc(tool->trace.tep, "osnoise", "sample_threshold",
buff, TRACEFS_HIST_KEY_NORMAL);
if (!data->trace_hist)
return 1;
retval = tracefs_hist_add_key(data->trace_hist, "cpu", 0);
if (retval)
goto out_err;
retval = tracefs_hist_start(tool->trace.inst, data->trace_hist);
if (retval)
goto out_err;
return 0;
out_err:
osnoise_destroy_trace_hist(tool);
return 1;
}
/*
* osnoise_read_trace_hist - parse histogram file and file osnoise histogram
*/
static void osnoise_read_trace_hist(struct osnoise_tool *tool)
{
struct osnoise_hist_data *data = tool->data;
long long cpu, counter, duration;
char *content, *position;
tracefs_hist_pause(tool->trace.inst, data->trace_hist);
content = tracefs_event_file_read(tool->trace.inst, "osnoise",
"sample_threshold",
"hist", NULL);
if (!content)
return;
position = content;
while (true) {
position = strstr(position, "duration: ~");
if (!position)
break;
position += strlen("duration: ~");
duration = get_llong_from_str(position);
if (duration == -1)
err_msg("error reading duration from histogram\n");
position = strstr(position, "cpu:");
if (!position)
break;
position += strlen("cpu: ");
cpu = get_llong_from_str(position);
if (cpu == -1)
err_msg("error reading cpu from histogram\n");
position = strstr(position, "hitcount:");
if (!position)
break;
position += strlen("hitcount: ");
counter = get_llong_from_str(position);
if (counter == -1)
err_msg("error reading counter from histogram\n");
osnoise_hist_update_multiple(tool, cpu, duration, counter);
}
free(content);
}
/*
* osnoise_hist_header - print the header of the tracer to the output
*/
static void osnoise_hist_header(struct osnoise_tool *tool)
{
struct osnoise_hist_params *params = tool->params;
struct osnoise_hist_data *data = tool->data;
struct trace_seq *s = tool->trace.seq;
char duration[26];
int cpu;
if (params->no_header)
return;
get_duration(tool->start_time, duration, sizeof(duration));
trace_seq_printf(s, "# RTLA osnoise histogram\n");
trace_seq_printf(s, "# Time unit is %s (%s)\n",
params->output_divisor == 1 ? "nanoseconds" : "microseconds",
params->output_divisor == 1 ? "ns" : "us");
trace_seq_printf(s, "# Duration: %s\n", duration);
if (!params->no_index)
trace_seq_printf(s, "Index");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
trace_seq_printf(s, " CPU-%03d", cpu);
}
trace_seq_printf(s, "\n");
trace_seq_do_printf(s);
trace_seq_reset(s);
}
/*
* osnoise_print_summary - print the summary of the hist data to the output
*/
static void
osnoise_print_summary(struct osnoise_hist_params *params,
struct trace_instance *trace,
struct osnoise_hist_data *data)
{
int cpu;
if (params->no_summary)
return;
if (!params->no_index)
trace_seq_printf(trace->seq, "count:");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].count);
}
trace_seq_printf(trace->seq, "\n");
if (!params->no_index)
trace_seq_printf(trace->seq, "min: ");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
trace_seq_printf(trace->seq, "%9llu ", data->hist[cpu].min_sample);
}
trace_seq_printf(trace->seq, "\n");
if (!params->no_index)
trace_seq_printf(trace->seq, "avg: ");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
if (data->hist[cpu].count)
trace_seq_printf(trace->seq, "%9llu ",
data->hist[cpu].sum_sample / data->hist[cpu].count);
else
trace_seq_printf(trace->seq, " - ");
}
trace_seq_printf(trace->seq, "\n");
if (!params->no_index)
trace_seq_printf(trace->seq, "max: ");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
trace_seq_printf(trace->seq, "%9llu ", data->hist[cpu].max_sample);
}
trace_seq_printf(trace->seq, "\n");
trace_seq_do_printf(trace->seq);
trace_seq_reset(trace->seq);
}
/*
* osnoise_print_stats - print data for all CPUs
*/
static void
osnoise_print_stats(struct osnoise_hist_params *params, struct osnoise_tool *tool)
{
struct osnoise_hist_data *data = tool->data;
struct trace_instance *trace = &tool->trace;
int bucket, cpu;
int total;
osnoise_hist_header(tool);
for (bucket = 0; bucket < data->entries; bucket++) {
total = 0;
if (!params->no_index)
trace_seq_printf(trace->seq, "%-6d",
bucket * data->bucket_size);
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
total += data->hist[cpu].samples[bucket];
trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].samples[bucket]);
}
if (total == 0 && !params->with_zeros) {
trace_seq_reset(trace->seq);
continue;
}
trace_seq_printf(trace->seq, "\n");
trace_seq_do_printf(trace->seq);
trace_seq_reset(trace->seq);
}
if (!params->no_index)
trace_seq_printf(trace->seq, "over: ");
for (cpu = 0; cpu < data->nr_cpus; cpu++) {
if (params->cpus && !params->monitored_cpus[cpu])
continue;
if (!data->hist[cpu].count)
continue;
trace_seq_printf(trace->seq, "%9d ",
data->hist[cpu].samples[data->entries]);
}
trace_seq_printf(trace->seq, "\n");
trace_seq_do_printf(trace->seq);
trace_seq_reset(trace->seq);
osnoise_print_summary(params, trace, data);
}
/*
* osnoise_hist_usage - prints osnoise hist usage message
*/
static void osnoise_hist_usage(char *usage)
{
int i;
static const char * const msg[] = {
"",
" usage: rtla osnoise hist [-h] [-D] [-d s] [-p us] [-r us] [-s us] [-S us] [-t[=file]] \\",
" [-c cpu-list] [-P priority] [-b N] [-e N] [--no-header] [--no-summary] \\",
" [--no-index] [--with-zeros]",
"",
" -h/--help: print this menu",
" -p/--period us: osnoise period in us",
" -r/--runtime us: osnoise runtime in us",
" -s/--stop us: stop trace if a single sample is higher than the argument in us",
" -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
" -c/--cpus cpu-list: list of cpus to run osnoise threads",
" -d/--duration time[s|m|h|d]: duration of the session",
" -D/--debug: print debug info",
" -t/--trace[=file]: save the stopped trace to [file|osnoise_trace.txt]",
" -b/--bucket-size N: set the histogram bucket size (default 1)",
" -e/--entries N: set the number of entries of the histogram (default 256)",
" --no-header: do not print header",
" --no-summary: do not print summary",
" --no-index: do not print index",
" --with-zeros: print zero only entries",
" -P/--priority o:prio|r:prio|f:prio|d:runtime:period: set scheduling parameters",
" o:prio - use SCHED_OTHER with prio",
" r:prio - use SCHED_RR with prio",
" f:prio - use SCHED_FIFO with prio",
" d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
" in nanoseconds",
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]);
exit(1);
}
/*
* osnoise_hist_parse_args - allocs, parse and fill the cmd line parameters
*/
static struct osnoise_hist_params
*osnoise_hist_parse_args(int argc, char *argv[])
{
struct osnoise_hist_params *params;
int retval;
int c;
params = calloc(1, sizeof(*params));
if (!params)
exit(1);
/* display data in microseconds */
params->output_divisor = 1000;
params->bucket_size = 1;
params->entries = 256;
while (1) {
static struct option long_options[] = {
{"bucket-size", required_argument, 0, 'b'},
{"entries", required_argument, 0, 'e'},
{"cpus", required_argument, 0, 'c'},
{"debug", no_argument, 0, 'D'},
{"duration", required_argument, 0, 'd'},
{"help", no_argument, 0, 'h'},
{"period", required_argument, 0, 'p'},
{"priority", required_argument, 0, 'P'},
{"runtime", required_argument, 0, 'r'},
{"stop", required_argument, 0, 's'},
{"stop-total", required_argument, 0, 'S'},
{"trace", optional_argument, 0, 't'},
{"no-header", no_argument, 0, '0'},
{"no-summary", no_argument, 0, '1'},
{"no-index", no_argument, 0, '2'},
{"with-zeros", no_argument, 0, '3'},
{0, 0, 0, 0}
};
/* getopt_long stores the option index here. */
int option_index = 0;
c = getopt_long(argc, argv, "c:b:d:e:Dhp:P:r:s:S:t::0123",
long_options, &option_index);
/* detect the end of the options. */
if (c == -1)
break;
switch (c) {
case 'b':
params->bucket_size = get_llong_from_str(optarg);
if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
osnoise_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
break;
case 'c':
retval = parse_cpu_list(optarg, &params->monitored_cpus);
if (retval)
osnoise_hist_usage("\nInvalid -c cpu list\n");
params->cpus = optarg;
break;
case 'D':
config_debug = 1;
break;
case 'd':
params->duration = parse_seconds_duration(optarg);
if (!params->duration)
osnoise_hist_usage("Invalid -D duration\n");
break;
case 'e':
params->entries = get_llong_from_str(optarg);
if ((params->entries < 10) || (params->entries > 9999999))
osnoise_hist_usage("Entries must be > 10 and < 9999999\n");
break;
case 'h':
case '?':
osnoise_hist_usage(NULL);
break;
case 'p':
params->period = get_llong_from_str(optarg);
if (params->period > 10000000)
osnoise_hist_usage("Period longer than 10 s\n");
break;
case 'P':
retval = parse_prio(optarg, &params->sched_param);
if (retval == -1)
osnoise_hist_usage("Invalid -P priority");
params->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");
break;
case 's':
params->stop_us = get_llong_from_str(optarg);
break;
case 'S':
params->stop_total_us = get_llong_from_str(optarg);
break;
case 't':
if (optarg)
/* skip = */
params->trace_output = &optarg[1];
else
params->trace_output = "osnoise_trace.txt";
break;
case '0': /* no header */
params->no_header = 1;
break;
case '1': /* no summary */
params->no_summary = 1;
break;
case '2': /* no index */
params->no_index = 1;
break;
case '3': /* with zeros */
params->with_zeros = 1;
break;
default:
osnoise_hist_usage("Invalid option");
}
}
if (geteuid()) {
err_msg("rtla needs root permission\n");
exit(EXIT_FAILURE);
}
if (params->no_index && !params->with_zeros)
osnoise_hist_usage("no-index set and with-zeros not set - it does not make sense");
return params;
}
/*
* osnoise_hist_apply_config - apply the hist configs to the initialized tool
*/
static int
osnoise_hist_apply_config(struct osnoise_tool *tool, struct osnoise_hist_params *params)
{
int retval;
if (!params->sleep_time)
params->sleep_time = 1;
if (params->cpus) {
retval = osnoise_set_cpus(tool->context, params->cpus);
if (retval) {
err_msg("Failed to apply CPUs config\n");
goto out_err;
}
}
if (params->runtime || params->period) {
retval = osnoise_set_runtime_period(tool->context,
params->runtime,
params->period);
if (retval) {
err_msg("Failed to set runtime and/or period\n");
goto out_err;
}
}
if (params->stop_us) {
retval = osnoise_set_stop_us(tool->context, params->stop_us);
if (retval) {
err_msg("Failed to set stop us\n");
goto out_err;
}
}
if (params->stop_total_us) {
retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
if (retval) {
err_msg("Failed to set stop total us\n");
goto out_err;
}
}
return 0;
out_err:
return -1;
}
/*
* osnoise_init_hist - initialize a osnoise hist tool with parameters
*/
static struct osnoise_tool
*osnoise_init_hist(struct osnoise_hist_params *params)
{
struct osnoise_tool *tool;
int nr_cpus;
nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
tool = osnoise_init_tool("osnoise_hist");
if (!tool)
return NULL;
tool->data = osnoise_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
if (!tool->data)
goto out_err;
tool->params = params;
return tool;
out_err:
osnoise_destroy_tool(tool);
return NULL;
}
static int stop_tracing;
static void stop_hist(int sig)
{
stop_tracing = 1;
}
/*
* osnoise_hist_set_signals - handles the signal to stop the tool
*/
static void
osnoise_hist_set_signals(struct osnoise_hist_params *params)
{
signal(SIGINT, stop_hist);
if (params->duration) {
signal(SIGALRM, stop_hist);
alarm(params->duration);
}
}
int osnoise_hist_main(int argc, char *argv[])
{
struct osnoise_hist_params *params;
struct trace_instance *trace;
struct osnoise_tool *record;
struct osnoise_tool *tool;
int return_value = 1;
int retval;
params = osnoise_hist_parse_args(argc, argv);
if (!params)
exit(1);
tool = osnoise_init_hist(params);
if (!tool) {
err_msg("Could not init osnoise hist\n");
goto out_exit;
}
retval = osnoise_hist_apply_config(tool, params);
if (retval) {
err_msg("Could not apply config\n");
goto out_destroy;
}
trace = &tool->trace;
retval = enable_osnoise(trace);
if (retval) {
err_msg("Failed to enable osnoise tracer\n");
goto out_destroy;
}
retval = osnoise_init_trace_hist(tool);
if (retval)
goto out_destroy;
if (params->set_sched) {
retval = set_comm_sched_attr("osnoise/", &params->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
goto out_hist;
}
}
trace_instance_start(trace);
if (params->trace_output) {
record = osnoise_init_trace_tool("osnoise");
if (!record) {
err_msg("Failed to enable the trace instance\n");
goto out_hist;
}
trace_instance_start(&record->trace);
}
tool->start_time = time(NULL);
osnoise_hist_set_signals(params);
while (!stop_tracing) {
sleep(params->sleep_time);
retval = tracefs_iterate_raw_events(trace->tep,
trace->inst,
NULL,
0,
collect_registered_events,
trace);
if (retval < 0) {
err_msg("Error iterating on events\n");
goto out_hist;
}
if (!tracefs_trace_is_on(trace->inst))
break;
};
osnoise_read_trace_hist(tool);
osnoise_print_stats(params, tool);
return_value = 0;
if (!tracefs_trace_is_on(trace->inst)) {
printf("rtla timelat hit stop tracing\n");
if (params->trace_output) {
printf(" Saving trace to %s\n", params->trace_output);
save_trace_to_file(record->trace.inst, params->trace_output);
}
}
out_hist:
osnoise_free_histogram(tool->data);
out_destroy:
osnoise_destroy_tool(tool);
if (params->trace_output)
osnoise_destroy_tool(record);
free(params);
out_exit:
exit(return_value);
}
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