Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 965 insertions, 0 deletions

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
new file mode 100644
index 0000000000..1640f121ba
--- /dev/null
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -0,0 +1,965 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
+ */
+
+#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;
+	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;
+}
+
+/*
+ * 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 osnoise_tool *top)
+{
+	struct timerlat_top_params *params = top->params;
+	struct trace_seq *s = top->trace.seq;
+	char duration[26];
+
+	get_duration(top->start_time, duration, sizeof(duration));
+
+	trace_seq_printf(s, "\033[2;37;40m");
+	trace_seq_printf(s, "                                     Timer Latency                                              ");
+	if (params->user_top)
+		trace_seq_printf(s, "                                         ");
+	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");
+	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");
+	trace_seq_printf(s, "\033[0;0;0m");
+	trace_seq_printf(s, "\n");
+}
+
+/*
+ * 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, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        - |");
+	} 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, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        -\n");
+	} 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, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        - ");
+		trace_seq_printf(s, "        -\n");
+	} 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);
+	}
+}
+
+/*
+ * 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;
+	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_header(top);
+
+	for (i = 0; i < nr_cpus; i++) {
+		if (params->cpus && !CPU_ISSET(i, &params->monitored_cpus))
+			continue;
+		timerlat_top_print(top, i);
+	}
+
+	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]",
+		"",
+		"	  -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[m|h|d]: duration of the session in seconds",
+		"	  -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 in-kernel timerlat threads",
+		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]);
+	exit(1);
+}
+
+/*
+ * 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'},
+			{"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'},
+			{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:np:P:qs:t::T:u0:1:2:345:",
+				 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, &params->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, &params->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 '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, &params->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)
+				/* skip = */
+				params->trace_output = &optarg[1];
+			else
+				params->trace_output = "timerlat_trace.txt";
+
+			break;
+		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;
+		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!");
+
+	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, &params->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),
+					   &params->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(&params->monitored_cpus);
+	}
+
+	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;
+		}
+	}
+
+	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/", &params->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->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;
+			}
+		}
+	}
+
+	/*
+	 * 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);
+
+	if (params->user_top) {
+		/* rtla asked to stop */
+		params_u.should_run = 1;
+		/* all threads left */
+		params_u.stopped_running = 0;
+
+		params_u.set = &params->monitored_cpus;
+		if (params->set_sched)
+			params_u.sched_param = &params->sched_param;
+		else
+			params_u.sched_param = NULL;
+
+		params_u.cgroup_name = params->cgroup_name;
+
+		retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
+		if (retval)
+			err_msg("Error creating timerlat user-space threads\n");
+	}
+
+	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_top) {
+			if (params_u.stopped_running) {
+				debug_msg("timerlat user space threads stopped!\n");
+				break;
+			}
+		}
+	}
+
+	if (params->user_top && !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);
+}