path: root/tools/tracing/rtla/src/timerlat_hist.c

// 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 <stdio.h>
#include <time.h>

#include "utils.h"
#include "osnoise.h"
#include "timerlat.h"

struct timerlat_hist_params {
	char			*cpus;
	char			*monitored_cpus;
	char			*trace_output;
	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			set_sched;
	int			dma_latency;
	struct sched_attr	sched_param;
	struct trace_events	*events;

	char			no_irq;
	char			no_thread;
	char			no_header;
	char			no_summary;
	char			no_index;
	char			with_zeros;
	int			bucket_size;
	int			entries;
};

struct timerlat_hist_cpu {
	int			*irq;
	int			*thread;

	int			irq_count;
	int			thread_count;

	unsigned long long	min_irq;
	unsigned long long	sum_irq;
	unsigned long long	max_irq;

	unsigned long long	min_thread;
	unsigned long long	sum_thread;
	unsigned long long	max_thread;
};

struct timerlat_hist_data {
	struct timerlat_hist_cpu	*hist;
	int				entries;
	int				bucket_size;
	int				nr_cpus;
};

/*
 * timerlat_free_histogram - free runtime data
 */
static void
timerlat_free_histogram(struct timerlat_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].irq)
			free(data->hist[cpu].irq);

		if (data->hist[cpu].thread)
			free(data->hist[cpu].thread);
	}

	/* one set of histograms per CPU */
	if (data->hist)
		free(data->hist);

	free(data);
}

/*
 * timerlat_alloc_histogram - alloc runtime data
 */
static struct timerlat_hist_data
*timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
{
	struct timerlat_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;

	/* one set of histograms per CPU */
	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
	if (!data->hist)
		goto cleanup;

	/* one histogram for IRQ and one for thread, per cpu */
	for (cpu = 0; cpu < nr_cpus; cpu++) {
		data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
		if (!data->hist[cpu].irq)
			goto cleanup;
		data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
		if (!data->hist[cpu].thread)
			goto cleanup;
	}

	/* set the min to max */
	for (cpu = 0; cpu < nr_cpus; cpu++) {
		data->hist[cpu].min_irq = ~0;
		data->hist[cpu].min_thread = ~0;
	}

	return data;

cleanup:
	timerlat_free_histogram(data);
	return NULL;
}

/*
 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
 */
static void
timerlat_hist_update(struct osnoise_tool *tool, int cpu,
		     unsigned long long thread,
		     unsigned long long latency)
{
	struct timerlat_hist_params *params = tool->params;
	struct timerlat_hist_data *data = tool->data;
	int entries = data->entries;
	int bucket;
	int *hist;

	if (params->output_divisor)
		latency = latency / params->output_divisor;

	if (data->bucket_size)
		bucket = latency / data->bucket_size;

	if (!thread) {
		hist = data->hist[cpu].irq;
		data->hist[cpu].irq_count++;
		update_min(&data->hist[cpu].min_irq, &latency);
		update_sum(&