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>
 */

#define _GNU_SOURCE
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>

#include "timerlat.h"
#include "timerlat_aa.h"
#include "timerlat_bpf.h"
#include "cli.h"
#include "common.h"

struct timerlat_hist_cpu {
	int			*irq;
	int			*thread;
	int			*user;

	unsigned long long	irq_count;
	unsigned long long	thread_count;
	unsigned long long	user_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;

	unsigned long long	min_user;
	unsigned long long	sum_user;
	unsigned long long	max_user;
};

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

/*
 * 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 < nr_cpus; cpu++) {
		if (data->hist[cpu].irq)
			free(data->hist[cpu].irq);

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

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

	}

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

static void timerlat_free_histogram_tool(struct osnoise_tool *tool)
{
	timerlat_free_histogram(tool->data);
	timerlat_free(tool);
}

/*
 * timerlat_alloc_histogram - alloc runtime data
 */
static struct timerlat_hist_data
*timerlat_alloc_histogram(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;

	/* 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;

		data->hist[cpu].user = calloc(1, sizeof(*data->hist->user) * (entries + 1));
		if (!data->hist[cpu].user)
			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;
		data->hist[cpu].min_user = ~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 context,
		     unsigned long long latency)
{
	struct timerlat_params *params = to_timerlat_params(tool->params);
	struct timerlat_hist_data *data = tool->data;
	int entries = data->entries;
	int bucket;
	int *hist;

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

	bucket = latency / data->bucket_size;

	if (!context) {
		hist = data->hist[cpu].irq;
		data->hist[cpu].irq_count++;
		update_min(&data->hist[cpu].min_irq, &latency);
		update_sum(&data->hist[cpu].sum_irq, &latency);
		update_max(&data->hist[cpu].max_irq, &latency);
	} else if (context == 1) {
		hist = data->hist[cpu].thread;
		data->hist[cpu].thread_count++;
		update_min(&data->hist[cpu].min_thread, &latency);
		update_sum(&data->hist[cpu].sum_thread, &latency);
		update_max(&data->hist[cpu].max_thread, &latency);
	} else { /* user */
		hist = data->hist[cpu].user;
		data->hist[cpu].user_count++;
		update_min(&