// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <[email protected]>
*/
#define _GNU_SOURCE
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <sched.h>
#include <pthread.h>
#include "utils.h"
#include "osnoise.h"
#include "timerlat.h"
#include "timerlat_aa.h"
#include "timerlat_u.h"
struct timerlat_top_params {
char *cpus;
cpu_set_t monitored_cpus;
char *trace_output;
char *cgroup_name;
unsigned long long runtime;
long long stop_us;
long long stop_total_us;
long long timerlat_period_us;
long long print_stack;
int sleep_time;
int output_divisor;
int duration;
int quiet;
int set_sched;
int dma_latency;
int no_aa;
int aa_only;
int dump_tasks;
int cgroup;
int hk_cpus;
int user_top;
int user_workload;
int kernel_workload;
int pretty_output;
int warmup;
int buffer_size;
cpu_set_t hk_cpu_set;
struct sched_attr sched_param;
struct trace_events *events;
};
struct timerlat_top_cpu {
int irq_count;
int thread_count;
int user_count;
unsigned long long cur_irq;
unsigned long long min_irq;
unsigned long long sum_irq;
unsigned long long max_irq;
unsigned long long cur_thread;
unsigned long long min_thread;
unsigned long long sum_thread;
unsigned long long max_thread;
unsigned long long cur_user;
unsigned long long min_user;
unsigned long long sum_user;
unsigned long long max_user;
};
struct timerlat_top_data {
struct timerlat_top_cpu *cpu_data;
int nr_cpus;
};
/*
* timerlat_free_top - free runtime data
*/
static void
timerlat_free_top(struct timerlat_top_data *data)
{
free(data->cpu_data);
free(data);
}
/*
* timerlat_alloc_histogram - alloc runtime data
*/
static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
{
struct timerlat_top_data *data;
int cpu;
data = calloc(1, sizeof(*data));
if (!data)
return NULL;
data->nr_cpus = nr_cpus;
/* one set of histograms per CPU */
data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
if (!data->cpu_data)
goto cleanup;
/* set the min to max */
for (cpu = 0; cpu < nr_cpus; cpu++) {
data->cpu_data[cpu].min_irq = ~0;
data->cpu_data[cpu].min_thread = ~0;
data->cpu_data[cpu].min_user = ~0;
}
return data;
cleanup:
timerlat_free_top(data);
return NULL;
}
static void
timerlat_top_reset_sum(struct timerlat_top_cpu *summary)
{
memset(summary, 0, sizeof(*summary));
summary->min_irq = ~0;
summary->min_thread = ~0;
summary->min_user = ~0;
}
static void
timerlat_top_update_sum(struct osnoise_tool *tool, int cpu, struct timerlat_top_cpu *sum)
{
struct timerlat_top_data *data = tool->data;
struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
sum->irq_count += cpu_data->irq_count;
update_min(&sum->min_irq, &cpu_data->min_irq);
update_sum(&sum->sum_irq, &cpu_data->sum_irq);
update_max(&sum->max_irq, &cpu_data->max_irq);
sum->thread_count += cpu_data->thread_count;
update_min(&sum->min_thread, &cpu_data->min_thread);
update_sum(&sum->sum_thread, &cpu_data->sum_thread);
update_max(&sum->max_thread, &cpu_data->max_thread);
sum->user_count += cpu_data->user_count;
update_min(&sum->min_user, &cpu_data->min_user);
update_sum(&sum->sum_user, &cpu_data->sum_user);
update_max(&sum->max_user, &cpu_data->max_user);
}
/*
* timerlat_hist_update - record a new timerlat occurent on cpu, updating data
*/
static void
timerlat_top_update(struct osnoise_tool *tool, int cpu,
unsigned long long thread,
unsigned long long latency)
{
struct timerlat_top_data *data = tool->data;
struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
if (!thread) {
cpu_data->irq_count++;
cpu_data->cur_irq = latency;
update_min(&cpu_data->min_irq, &latency);
update_sum(&cpu_data->sum_irq, &latency);
update_max(&cpu_data->max_irq, &latency);
} else if (thread == 1) {
cpu_data->thread_count++;
cpu_data->cur_thread = latency;
update_min(&cpu_data->min_thread, &latency);
update_sum(&cpu_data->sum_thread, &latency);
update_max(&cpu_data->max_thread, &latency);
} else {
cpu_data->user_count++;
cpu_data->cur_user = latency;
update_min(&cpu_data->min_user, &latency);
update_sum(&cpu_data->sum_user, &latency);
update_max(&cpu_data->max_user, &latency);
}
}
/*
* timerlat_top_handler - this is the handler for timerlat tracer events
*/
static int
timerlat_top_handler(struct trace_seq *s, struct tep_record *record,
struct tep_event *event, void *context)
{
struct trace_instance *trace = context;
struct timerlat_top_params *params;
unsigned long long latency, thread;
struct osnoise_tool *top;
int cpu = record->cpu;
top = container_of(trace, struct osnoise_tool, trace);
params = top->params;
if (!params->aa_only) {
tep_get_field_val(s, event, "context", record, &thread, 1);
tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
timerlat_top_update(top, cpu, thread, latency);
}
return 0;
}
/*
* timerlat_top_header - print the header of the tool output
*/
static void timerlat_top_header(struct timerlat_top_params *params, struct osnoise_tool *top)
{
struct trace_seq *s = top->trace.seq;
char duration[26];
get_duration(top->start_time, duration, sizeof(duration));
if (params->pretty_output)
trace_seq_printf(s, "\033[2;37;40m");
trace_seq_printf(s, " Timer Latency ");
if (params->user_top)
trace_seq_printf(s, " ");
if (params->pretty_output)
trace_seq_printf(s, "\033[0;0;0m");
trace_seq_printf(s, "\n");
trace_seq_printf(s, "%-6s | IRQ Timer Latency (%s) | Thread Timer Latency (%s)", duration,
params->output_divisor == 1 ? "ns" : "us",
params->output_divisor == 1 ? "ns" : "us");
if (params->user_top) {
trace_seq_printf(s, " | Ret user Timer Latency (%s)",
params->output_divisor == 1 ? "ns" : "us");
}
trace_seq_printf(s, "\n");
if (params->pretty_output)
trace_seq_printf(s, "\033[2;30;47m");
trace_seq_printf(s, "CPU COUNT | cur min avg max | cur min avg max");
if (params->user_top)
trace_seq_printf(s, " | cur min avg max");
if (params->pretty_output)
trace_seq_printf(s, "\033[0;0;0m");
trace_seq_printf(s, "\n");
}
static const char *no_value = " -";
/*
* timerlat_top_print - prints the output of a given CPU
*/
static void timerlat_top_print(struct osnoise_tool *top, int cpu)
{
struct timerlat_top_params *params = top->params;
struct timerlat_top_data *data = top->data;
struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
int divisor = params->output_divisor;
struct trace_seq *s = top->trace.seq;
if (divisor == 0)
return;
/*
* Skip if no data is available: is this cpu offline?
*/
if (!cpu_data->irq_count && !cpu_data->thread_count)
return;
/*
* Unless trace is being lost, IRQ counter is always the max.
*/
trace_seq_printf(s, "%3d #%-9d |", cpu, cpu_data->irq_count);
if (!cpu_data->irq_count) {
trace_seq_printf(s, "%s %s %s %s |", no_value, no_value, no_value, no_value);
} else {
trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor);
trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor);
trace_seq_printf(s, "%9llu ", (cpu_data->sum_irq / cpu_data->irq_count) / divisor);
trace_seq_printf(s, "%9llu |", cpu_data->max_irq / divisor);
}
if (!cpu_data->thread_count) {
trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
} else {
trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor);
trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor);
trace_seq_printf(s, "%9llu ",
(cpu_data->sum_thread / cpu_data->thread_count) / divisor);
trace_seq_printf(s, "%9llu", cpu_data->max_thread / divisor);
}
if (!params->user_top) {
trace_seq_printf(s, "\n");
return;
}
trace_seq_printf(s, " |");
if (!cpu_data->user_count) {
trace_seq_printf(s, "%s %s %s %s\n", no_value, no_value, no_value, no_value);
} else {
trace_seq_printf(s, "%9llu ", cpu_data->cur_user / divisor);
trace_seq_printf(s, "%9llu ", cpu_data->min_user / divisor);
trace_seq_printf(s, "%9llu ",
(cpu_data->sum_user / cpu_data->user_count) / divisor);
trace_seq_printf(s, "%9llu\n", cpu_data->max_user / divisor);
}
}
/*
* timerlat_top_print_sum - prints the summary output
*/
static void
timerlat_top_print_sum(struct osnoise_tool *top, struct timerlat_top_cpu *summary)
{
const char *split = "----------------------------------------";
struct timerlat_top_params *params = top->params;
unsigned long long count = summary->irq_count;
int divisor = params->output_divisor;
struct trace_seq *s = top->trace.seq;
int e = 0;
if (divisor == 0)
return;
/*
* Skip if no data is available: is this cpu offline?
*/
if (!summary->irq_count && !summary->thread_count)
return;
while (count > 999999) {
e++;
count /= 10;
}
trace_seq_printf(s, "%.*s|%.*s|%.*s", 15, split, 40, split, 39, split);
if (params->user_top)
trace_seq_printf(s, "-|%.*s", 39, split);
trace_seq_printf(s, "\n");
trace_seq_printf(s, "ALL #%-6llu e%d |", count, e);
if (!summary->irq_count) {
trace_seq_printf(s, " %s %s %s |", no_value, no_value, no_value);
} else {
trace_seq_printf(s, " ");
trace_seq_printf(s, "%9llu ", summary->min_irq / params->output_divisor);
trace_seq_printf(s, "%9llu ", (summary->sum_irq / summary->irq_count) / divisor);
trace_seq_printf(s, "%9llu |", summary->max_irq / divisor);
}
if (!summary->thread_count) {
trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
} else {
trace_seq_printf(s, " ");
trace_seq_printf(s, "%9llu ", summary->min_thread / divisor);
trace_seq_printf(s, "%9llu ",
(summary->sum_thread / summary->thread_count) / divisor);
trace_seq_printf(s, "%9llu", summary->max_thread / divisor);
}
if (!params->user_top) {
trace_seq_printf(s, "\n");
return;
}
trace_seq_printf(s, " |");
if (!summary->user_count) {
trace_seq_printf(s, " %s %s %s |", no_value, no_value, no_value);
} else {
trace_seq_printf(s, " ");
trace_seq_printf(s, "%9llu ", summary->min_user / divisor);
trace_seq_printf(s, "%9llu ",
(summary->sum_user / summary->user_count) / divisor);
trace_seq_printf(s, "%9llu\n", summary->max_user / divisor);
}
}
/*
* clear_terminal - clears the output terminal
*/
static void clear_terminal(struct trace_seq *seq)
{
if (!config_debug)
trace_seq_printf(seq, "\033c");
}
/*
* timerlat_print_stats - print data for all cpus
*/
static void
timerlat_print_stats(struct timerlat_top_params *params, struct osnoise_tool *top)
{
struct trace_instance *trace = &top->trace;
struct timerlat_top_cpu summary;
static int nr_cpus = -1;
int i;
if (params->aa_only)
return;
if (nr_cpus == -1)
nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
if (!params->quiet)
clear_terminal(trace->seq);
timerlat_top_reset_sum(&summary);
timerlat_top_header(params, top);
for (i = 0; i < nr_cpus; i++) {
if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
continue;
timerlat_top_print(top, i);
timerlat_top_update_sum(top, i, &summary);
}
timerlat_top_print_sum(top, &summary);
trace_seq_do_printf(trace->seq);
trace_seq_reset(trace->seq);
}
/*
* timerlat_top_usage - prints timerlat top usage message
*/
static void timerlat_top_usage(char *usage)
{
int i;
static const char *const msg[] = {
"",
" usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
" [[-t[file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
" [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u|-k] [--warm-up s]",
"",
" -h/--help: print this menu",
" -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
" --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
" -p/--period us: timerlat period in us",
" -i/--irq us: stop trace if the irq latency is higher than the argument in us",
" -T/--thread us: stop trace if the thread latency is higher than the argument in us",
" -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
" -c/--cpus cpus: run the tracer only on the given cpus",
" -H/--house-keeping cpus: run rtla control threads only on the given cpus",
" -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
" -d/--duration time[s|m|h|d]: duration of the session",
" -D/--debug: print debug info",
" --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
" -t/--trace[file]: save the stopped trace to [file|timerlat_trace.txt]",
" -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
" --filter <command>: enable a trace event filter to the previous -e event",
" --trigger <command>: enable a trace event trigger to the previous -e event",
" -n/--nano: display data in nanoseconds",
" --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
" -q/--quiet print only a summary at the end",
" --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
" -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",
" -u/--user-threads: use rtla user-space threads instead of kernel-space timerlat threads",
" -k/--kernel-threads: use timerlat kernel-space threads instead of rtla user-space threads",
" -U/--user-load: enable timerlat for user-defined user-space workload",
" --warm-up s: let the workload run for s seconds before collecting data",
" --trace-buffer-size kB: set the per-cpu trace buffer size in kB",
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);
}
/*
* timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
*/
static struct timerlat_top_params
*timerlat_top_parse_args(int argc, char **argv)
{
struct timerlat_top_params *params;
struct trace_events *tevent;
long long auto_thresh;
int retval;
int c;
params = calloc(1, sizeof(*params));
if (!params)
exit(1);
/* disabled by default */
params->dma_latency = -1;
/* display data in microseconds */
params->output_divisor = 1000;
while (1) {
static struct option long_options[] = {
{"auto", required_argument, 0, 'a'},
{"cpus", required_argument, 0, 'c'},
{"cgroup", optional_argument, 0, 'C'},
{"debug", no_argument, 0, 'D'},
{"duration", required_argument, 0, 'd'},
{"event", required_argument, 0, 'e'},
{"help", no_argument, 0, 'h'},
{"house-keeping", required_argument, 0, 'H'},
{"irq", required_argument, 0, 'i'},
{"nano", no_argument, 0, 'n'},
{"period", required_argument, 0, 'p'},
{"priority", required_argument, 0, 'P'},
{"quiet", no_argument, 0, 'q'},
{"stack", required_argument, 0, 's'},
{"thread", required_argument, 0, 'T'},
{"trace", optional_argument, 0, 't'},
{"user-threads", no_argument, 0, 'u'},
{"kernel-threads", no_argument, 0, 'k'},
{"user-load", no_argument, 0, 'U'},
{"trigger", required_argument, 0, '0'},
{"filter", required_argument, 0, '1'},
{"dma-latency", required_argument, 0, '2'},
{"no-aa", no_argument, 0, '3'},
{"dump-tasks", no_argument, 0, '4'},
{"aa-only", required_argument, 0, '5'},
{"warm-up", required_argument, 0, '6'},
{"trace-buffer-size", required_argument, 0, '7'},
{0, 0, 0, 0}
};
/* getopt_long stores the option index here. */
int option_index = 0;
c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:knp:P:qs:t::T:uU0:1:2:345:6:7:",
long_options, &option_index);
/* detect the end of the options. */
if (c == -1)
break;
switch (c) {
case 'a':
auto_thresh = get_llong_from_str(optarg);
/* set thread stop to auto_thresh */
params->stop_total_us = auto_thresh;
params->stop_us = auto_thresh;
/* get stack trace */
params->print_stack = auto_thresh;
/* set trace */
params->trace_output = "timerlat_trace.txt";
break;
case '5':
/* it is here because it is similar to -a */
auto_thresh = get_llong_from_str(optarg);
/* set thread stop to auto_thresh */
params->stop_total_us = auto_thresh;
params->stop_us = auto_thresh;
/* get stack trace */
params->print_stack = auto_thresh;
/* set aa_only to avoid parsing the trace */
params->aa_only = 1;
break;
case 'c':
retval = parse_cpu_set(optarg, ¶ms->monitored_cpus);
if (retval)
timerlat_top_usage("\nInvalid -c cpu list\n");
params->cpus = optarg;
break;
case 'C':
params->cgroup = 1;
if (!optarg) {
/* will inherit this cgroup */
params->cgroup_name = NULL;
} else if (*optarg == '=') {
/* skip the = */
params->cgroup_name = ++optarg;
}
break;
case 'D':
config_debug = 1;
break;
case 'd':
params->duration = parse_seconds_duration(optarg);
if (!params->duration)
timerlat_top_usage("Invalid -d duration\n");
break;
case 'e':
tevent = trace_event_alloc(optarg);
if (!tevent) {
err_msg("Error alloc trace event");
exit(EXIT_FAILURE);
}
if (params->events)
tevent->next = params->events;
params->events = tevent;
break;
case 'h':
case '?':
timerlat_top_usage(NULL);
break;
case 'H':
params->hk_cpus = 1;
retval = parse_cpu_set(optarg, ¶ms->hk_cpu_set);
if (retval) {
err_msg("Error parsing house keeping CPUs\n");
exit(EXIT_FAILURE);
}
break;
case 'i':
params->stop_us = get_llong_from_str(optarg);
break;
case 'k':
params->kernel_workload = true;
break;
case 'n':
params->output_divisor = 1;
break;
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");
break;
case 'P':
retval = parse_prio(optarg, ¶ms->sched_param);
if (retval == -1)
timerlat_top_usage("Invalid -P priority");
params->set_sched = 1;
break;
case 'q':
params->quiet = 1;
break;
case 's':
params->print_stack = get_llong_from_str(optarg);
break;
case 'T':
params->stop_total_us = get_llong_from_str(optarg);
break;
case 't':
if (optarg) {
if (optarg[0] == '=')
params->trace_output = &optarg[1];
else
params->trace_output = &optarg[0];
} else if (optind < argc && argv[optind][0] != '-')
params->trace_output = argv[optind];
else
params->trace_output = "timerlat_trace.txt";
break;
case 'u':
params->user_workload = true;
/* fallback: -u implies -U */
case 'U':
params->user_top = true;
break;
case '0': /* trigger */
if (params->events) {
retval = trace_event_add_trigger(params->events, optarg);
if (retval) {
err_msg("Error adding trigger %s\n", optarg);
exit(EXIT_FAILURE);
}
} else {
timerlat_top_usage("--trigger requires a previous -e\n");
}
break;
case '1': /* filter */
if (params->events) {
retval = trace_event_add_filter(params->events, optarg);
if (retval) {
err_msg("Error adding filter %s\n", optarg);
exit(EXIT_FAILURE);
}
} 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);
}
break;
case '3': /* no-aa */
params->no_aa = 1;
break;
case '4':
params->dump_tasks = 1;
break;
case '6':
params->warmup = get_llong_from_str(optarg);
break;
case '7':
params->buffer_size = get_llong_from_str(optarg);
break;
default:
timerlat_top_usage("Invalid option");
}
}
if (geteuid()) {
err_msg("rtla needs root permission\n");
exit(EXIT_FAILURE);
}
/*
* Auto analysis only happens if stop tracing, thus:
*/
if (!params->stop_us && !params->stop_total_us)
params->no_aa = 1;
if (params->no_aa && params->aa_only)
timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
if (params->kernel_workload && params->user_workload)
timerlat_top_usage("--kernel-threads and --user-threads are mutually exclusive!");
return params;
}
/*
* timerlat_top_apply_config - apply the top configs to the initialized tool
*/
static int
timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params)
{
int retval;
int i;
if (!params->sleep_time)
params->sleep_time = 1;
if (params->cpus) {
retval = osnoise_set_cpus(top->context, params->cpus);
if (retval) {
err_msg("Failed to apply CPUs config\n");
goto out_err;
}
} else {
for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
CPU_SET(i, ¶ms->monitored_cpus);
}
if (params->stop_us) {
retval = osnoise_set_stop_us(top->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(top->context, params->stop_total_us);
if (retval) {
err_msg("Failed to set stop total us\n");
goto out_err;
}
}
if (params->timerlat_period_us) {
retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us);
if (retval) {
err_msg("Failed to set timerlat period\n");
goto out_err;
}
}
if (params->print_stack) {
retval = osnoise_set_print_stack(top->context, params->print_stack);
if (retval) {
err_msg("Failed to set print stack\n");
goto out_err;
}
}
if (params->hk_cpus) {
retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
¶ms->hk_cpu_set);
if (retval == -1) {
err_msg("Failed to set rtla to the house keeping CPUs\n");
goto out_err;
}
} else if (params->cpus) {
/*
* Even if the user do not set a house-keeping CPU, try to
* move rtla to a CPU set different to the one where the user
* set the workload to run.
*
* No need to check results as this is an automatic attempt.
*/
auto_house_keeping(¶ms->monitored_cpus);
}
/*
* If the user did not specify a type of thread, try user-threads first.
* Fall back to kernel threads otherwise.
*/
if (!params->kernel_workload && !params->user_workload) {
retval = tracefs_file_exists(NULL, "osnoise/per_cpu/cpu0/timerlat_fd");
if (retval) {
debug_msg("User-space interface detected, setting user-threads\n");
params->user_workload = 1;
params->user_top = 1;
} else {
debug_msg("User-space interface not detected, setting kernel-threads\n");
params->kernel_workload = 1;
}
}
if (params->user_top) {
retval = osnoise_set_workload(top->context, 0);
if (retval) {
err_msg("Failed to set OSNOISE_WORKLOAD option\n");
goto out_err;
}
}
if (isatty(1) && !params->quiet)
params->pretty_output = 1;
return 0;
out_err:
return -1;
}
/*
* timerlat_init_top - initialize a timerlat top tool with parameters
*/
static struct osnoise_tool
*timerlat_init_top(struct timerlat_top_params *params)
{
struct osnoise_tool *top;
int nr_cpus;
nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
top = osnoise_init_tool("timerlat_top");
if (!top)
return NULL;
top->data = timerlat_alloc_top(nr_cpus);
if (!top->data)
goto out_err;
top->params = params;
tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
timerlat_top_handler, top);
return top;
out_err:
osnoise_destroy_tool(top);
return NULL;
}
static int stop_tracing;
static void stop_top(int sig)
{
stop_tracing = 1;
}
/*
* timerlat_top_set_signals - handles the signal to stop the tool
*/
static void
timerlat_top_set_signals(struct timerlat_top_params *params)
{
signal(SIGINT, stop_top);
if (params->duration) {
signal(SIGALRM, stop_top);
alarm(params->duration);
}
}
int timerlat_top_main(int argc, char *argv[])
{
struct timerlat_top_params *params;
struct osnoise_tool *record = NULL;
struct timerlat_u_params params_u;
struct osnoise_tool *top = NULL;
struct osnoise_tool *aa = NULL;
struct trace_instance *trace;
int dma_latency_fd = -1;
pthread_t timerlat_u;
int return_value = 1;
char *max_lat;
int retval;
params = timerlat_top_parse_args(argc, argv);
if (!params)
exit(1);
top = timerlat_init_top(params);
if (!top) {
err_msg("Could not init osnoise top\n");
goto out_exit;
}
retval = timerlat_top_apply_config(top, params);
if (retval) {
err_msg("Could not apply config\n");
goto out_free;
}
trace = &top->trace;
retval = enable_timerlat(trace);
if (retval) {
err_msg("Failed to enable timerlat tracer\n");
goto out_free;
}
if (params->set_sched) {
retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param);
if (retval) {
err_msg("Failed to set sched parameters\n");
goto out_free;
}
}
if (params->cgroup && !params->user_top) {
retval = set_comm_cgroup("timerlat/", params->cgroup_name);
if (!retval) {
err_msg("Failed to move threads to cgroup\n");
goto out_free;
}
}
if (params->dma_latency >= 0) {
dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
if (dma_latency_fd < 0) {
err_msg("Could not set /dev/cpu_dma_latency.\n");
goto out_free;
}
}
if (params->trace_output) {
record = osnoise_init_trace_tool("timerlat");
if (!record) {
err_msg("Failed to enable the trace instance\n");
goto out_free;
}
if (params->events) {
retval = trace_events_enable(&record->trace, params->events);
if (retval)
goto out_top;
}
if (params->buffer_size > 0) {
retval = trace_set_buffer_size(&record->trace, params->buffer_size);
if (retval)
goto out_top;
}
}
if (!params->no_aa) {
if (params->aa_only) {
/* as top is not used for display, use it for aa */
aa = top;
} else {
/* otherwise, a new instance is needed */
aa = osnoise_init_tool("timerlat_aa");
if (!aa)
goto out_top;
}
retval = timerlat_aa_init(aa, params->dump_tasks);
if (retval) {
err_msg("Failed to enable the auto analysis instance\n");
goto out_top;
}
/* if it is re-using the main instance, there is no need to start it */
if (aa != top) {
retval = enable_timerlat(&aa->trace);
if (retval) {
err_msg("Failed to enable timerlat tracer\n");
goto out_top;
}
}
}
if (params->user_workload) {
/* rtla asked to stop */
params_u.should_run = 1;
/* all threads left */
params_u.stopped_running = 0;
params_u.set = ¶ms->monitored_cpus;
if (params->set_sched)
params_u.sched_param = ¶ms->sched_param;
else
params_u.sched_param = NULL;
params_u.cgroup_name = params->cgroup_name;
retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, ¶ms_u);
if (retval)
err_msg("Error creating timerlat user-space threads\n");
}
if (params->warmup > 0) {
debug_msg("Warming up for %d seconds\n", params->warmup);
sleep(params->warmup);
}
/*
* Start the tracers here, after having set all instances.
*
* Let the trace instance start first for the case of hitting a stop
* tracing while enabling other instances. The trace instance is the
* one with most valuable information.
*/
if (params->trace_output)
trace_instance_start(&record->trace);
if (!params->no_aa && aa != top)
trace_instance_start(&aa->trace);
trace_instance_start(trace);
top->start_time = time(NULL);
timerlat_top_set_signals(params);
while (!stop_tracing) {
sleep(params->sleep_time);
if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
continue;
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_top;
}
if (!params->quiet)
timerlat_print_stats(params, top);
if (trace_is_off(&top->trace, &record->trace))
break;
/* is there still any user-threads ? */
if (params->user_workload) {
if (params_u.stopped_running) {
debug_msg("timerlat user space threads stopped!\n");
break;
}
}
}
if (params->user_workload && !params_u.stopped_running) {
params_u.should_run = 0;
sleep(1);
}
timerlat_print_stats(params, top);
return_value = 0;
if (trace_is_off(&top->trace, &record->trace)) {
printf("rtla timerlat hit stop tracing\n");
if (!params->no_aa)
timerlat_auto_analysis(params->stop_us, params->stop_total_us);
if (params->trace_output) {
printf(" Saving trace to %s\n", params->trace_output);
save_trace_to_file(record->trace.inst, params->trace_output);
}
} else if (params->aa_only) {
/*
* If the trace did not stop with --aa-only, at least print the
* max known latency.
*/
max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL);
if (max_lat) {
printf(" Max latency was %s\n", max_lat);
free(max_lat);
}
}
out_top:
timerlat_aa_destroy();
if (dma_latency_fd >= 0)
close(dma_latency_fd);
trace_events_destroy(&record->trace, params->events);
params->events = NULL;
out_free:
timerlat_free_top(top->data);
if (aa && aa != top)
osnoise_destroy_tool(aa);
osnoise_destroy_tool(record);
osnoise_destroy_tool(top);
free(params);
out_exit:
exit(return_value);
}
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