event.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2013, Michael Ellerman, IBM Corp.
  4 */
  5
  6#define _GNU_SOURCE
  7#include <unistd.h>
  8#include <sys/syscall.h>
  9#include <string.h>
 10#include <stdio.h>
 11#include <stdbool.h>
 12#include <sys/ioctl.h>
 13
 14#include "event.h"
 15
 16
 17int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
 18		int group_fd, unsigned long flags)
 19{
 20	return syscall(__NR_perf_event_open, attr, pid, cpu,
 21			   group_fd, flags);
 22}
 23
 24static void  __event_init_opts(struct event *e, u64 config,
 25			       int type, char *name, bool sampling)
 26{
 27	memset(e, 0, sizeof(*e));
 28
 29	e->name = name;
 30
 31	e->attr.type = type;
 32	e->attr.config = config;
 33	e->attr.size = sizeof(e->attr);
 34	/* This has to match the structure layout in the header */
 35	e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
 36				  PERF_FORMAT_TOTAL_TIME_RUNNING;
 37	if (sampling) {
 38		e->attr.sample_period = 1000;
 39		e->attr.sample_type = PERF_SAMPLE_REGS_INTR;
 40		e->attr.disabled = 1;
 41	}
 42}
 43
 44void event_init_opts(struct event *e, u64 config, int type, char *name)
 45{
 46	__event_init_opts(e, config, type, name, false);
 47}
 48
 49void event_init_named(struct event *e, u64 config, char *name)
 50{
 51	event_init_opts(e, config, PERF_TYPE_RAW, name);
 52}
 53
 54void event_init(struct event *e, u64 config)
 55{
 56	event_init_opts(e, config, PERF_TYPE_RAW, "event");
 57}
 58
 59void event_init_sampling(struct event *e, u64 config)
 60{
 61	__event_init_opts(e, config, PERF_TYPE_RAW, "event", true);
 62}
 63
 64#define PERF_CURRENT_PID	0
 65#define PERF_NO_PID		-1
 66#define PERF_NO_CPU		-1
 67#define PERF_NO_GROUP		-1
 68
 69int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
 70{
 71	e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
 72	if (e->fd == -1) {
 73		perror("perf_event_open");
 74		return -1;
 75	}
 76
 77	return 0;
 78}
 79
 80int event_open_with_group(struct event *e, int group_fd)
 81{
 82	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
 83}
 84
 85int event_open_with_pid(struct event *e, pid_t pid)
 86{
 87	return event_open_with_options(e, pid, PERF_NO_CPU, PERF_NO_GROUP);
 88}
 89
 90int event_open_with_cpu(struct event *e, int cpu)
 91{
 92	return event_open_with_options(e, PERF_NO_PID, cpu, PERF_NO_GROUP);
 93}
 94
 95int event_open(struct event *e)
 96{
 97	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
 98}
 99
100void event_close(struct event *e)
101{
102	close(e->fd);
103}
104
105int event_enable(struct event *e)
106{
107	return ioctl(e->fd, PERF_EVENT_IOC_ENABLE);
108}
109
110int event_disable(struct event *e)
111{
112	return ioctl(e->fd, PERF_EVENT_IOC_DISABLE);
113}
114
115int event_reset(struct event *e)
116{
117	return ioctl(e->fd, PERF_EVENT_IOC_RESET);
118}
119
120int event_read(struct event *e)
121{
122	int rc;
123
124	rc = read(e->fd, &e->result, sizeof(e->result));
125	if (rc != sizeof(e->result)) {
126		fprintf(stderr, "read error on event %p!\n", e);
127		return -1;
128	}
129
130	return 0;
131}
132
133void event_report_justified(struct event *e, int name_width, int result_width)
134{
135	printf("%*s: result %*llu ", name_width, e->name, result_width,
136	       e->result.value);
137
138	if (e->result.running == e->result.enabled)
139		printf("running/enabled %llu\n", e->result.running);
140	else
141		printf("running %llu enabled %llu\n", e->result.running,
142			e->result.enabled);
143}
144
145void event_report(struct event *e)
146{
147	event_report_justified(e, 0, 0);
148}