tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2013, Michael Ellerman, IBM Corp.
3 * Licensed under GPLv2.
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 <sys/ioctl.h>
12
13#include "event.h"
14
15
16int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
17 int group_fd, unsigned long flags)
18{
19 return syscall(__NR_perf_event_open, attr, pid, cpu,
20 group_fd, flags);
21}
22
23void event_init_opts(struct event *e, u64 config, int type, char *name)
24{
25 memset(e, 0, sizeof(*e));
26
27 e->name = name;
28
29 e->attr.type = type;
30 e->attr.config = config;
31 e->attr.size = sizeof(e->attr);
32 /* This has to match the structure layout in the header */
33 e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
34 PERF_FORMAT_TOTAL_TIME_RUNNING;
35}
36
37void event_init_named(struct event *e, u64 config, char *name)
38{
39 event_init_opts(e, config, PERF_TYPE_RAW, name);
40}
41
42#define PERF_CURRENT_PID 0
43#define PERF_NO_CPU -1
44#define PERF_NO_GROUP -1
45
46int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
47{
48 e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
49 if (e->fd == -1) {
50 perror("perf_event_open");
51 return -1;
52 }
53
54 return 0;
55}
56
57int event_open_with_group(struct event *e, int group_fd)
58{
59 return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
60}
61
62int event_open(struct event *e)
63{
64 return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
65}
66
67void event_close(struct event *e)
68{
69 close(e->fd);
70}
71
72int event_reset(struct event *e)
73{
74 return ioctl(e->fd, PERF_EVENT_IOC_RESET);
75}
76
77int event_read(struct event *e)
78{
79 int rc;
80
81 rc = read(e->fd, &e->result, sizeof(e->result));
82 if (rc != sizeof(e->result)) {
83 fprintf(stderr, "read error on event %p!\n", e);
84 return -1;
85 }
86
87 return 0;
88}
89
90void event_report_justified(struct event *e, int name_width, int result_width)
91{
92 printf("%*s: result %*llu ", name_width, e->name, result_width,
93 e->result.value);
94
95 if (e->result.running == e->result.enabled)
96 printf("running/enabled %llu\n", e->result.running);
97 else
98 printf("running %llu enabled %llu\n", e->result.running,
99 e->result.enabled);
100}
101
102void event_report(struct event *e)
103{
104 event_report_justified(e, 0, 0);
105}