path: root/tools/tracing/rtla/src/osnoise_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 <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <sched.h>

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

struct osnoise_hist_params {
	char			*cpus;
	cpu_set_t		monitored_cpus;
	char			*trace_output;
	char			*cgroup_name;
	unsigned long long	runtime;
	unsigned long long	period;
	long long		threshold;
	long long		stop_us;
	long long		stop_total_us;
	int			sleep_time;
	int			duration;
	int			set_sched;
	int			output_divisor;
	int			cgroup;
	int			hk_cpus;
	cpu_set_t		hk_cpu_set;
	struct sched_attr	sched_param;
	struct trace_events	*events;
	char			no_header;
	char			no_summary;
	char			no_index;
	char			with_zeros;
	int			bucket_size;
	int			entries;
	int			warmup;
	int			buffer_size;
};

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;
	unsigned long long total_duration;
	int entries = data->entries;
	int bucket;
	int *hist;

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

	bucket = duration / data->bucket_size;

	total_duration = duration * count;

	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, &total_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->tra