tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include "evsel.h"
2#include "tests.h"
3#include "thread_map.h"
4#include "cpumap.h"
5#include "debug.h"
6
7int test__open_syscall_event_on_all_cpus(void)
8{
9 int err = -1, fd, cpu;
10 struct cpu_map *cpus;
11 struct perf_evsel *evsel;
12 unsigned int nr_open_calls = 111, i;
13 cpu_set_t cpu_set;
14 struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
15 char sbuf[STRERR_BUFSIZE];
16
17 if (threads == NULL) {
18 pr_debug("thread_map__new\n");
19 return -1;
20 }
21
22 cpus = cpu_map__new(NULL);
23 if (cpus == NULL) {
24 pr_debug("cpu_map__new\n");
25 goto out_thread_map_delete;
26 }
27
28 CPU_ZERO(&cpu_set);
29
30 evsel = perf_evsel__newtp("syscalls", "sys_enter_open");
31 if (evsel == NULL) {
32 pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
33 goto out_thread_map_delete;
34 }
35
36 if (perf_evsel__open(evsel, cpus, threads) < 0) {
37 pr_debug("failed to open counter: %s, "
38 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
39 strerror_r(errno, sbuf, sizeof(sbuf)));
40 goto out_evsel_delete;
41 }
42
43 for (cpu = 0; cpu < cpus->nr; ++cpu) {
44 unsigned int ncalls = nr_open_calls + cpu;
45 /*
46 * XXX eventually lift this restriction in a way that
47 * keeps perf building on older glibc installations
48 * without CPU_ALLOC. 1024 cpus in 2010 still seems
49 * a reasonable upper limit tho :-)
50 */
51 if (cpus->map[cpu] >= CPU_SETSIZE) {
52 pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
53 continue;
54 }
55
56 CPU_SET(cpus->map[cpu], &cpu_set);
57 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
58 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
59 cpus->map[cpu],
60 strerror_r(errno, sbuf, sizeof(sbuf)));
61 goto out_close_fd;
62 }
63 for (i = 0; i < ncalls; ++i) {
64 fd = open("/etc/passwd", O_RDONLY);
65 close(fd);
66 }
67 CPU_CLR(cpus->map[cpu], &cpu_set);
68 }
69
70 /*
71 * Here we need to explicitely preallocate the counts, as if
72 * we use the auto allocation it will allocate just for 1 cpu,
73 * as we start by cpu 0.
74 */
75 if (perf_evsel__alloc_counts(evsel, cpus->nr) < 0) {
76 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
77 goto out_close_fd;
78 }
79
80 err = 0;
81
82 for (cpu = 0; cpu < cpus->nr; ++cpu) {
83 unsigned int expected;
84
85 if (cpus->map[cpu] >= CPU_SETSIZE)
86 continue;
87
88 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
89 pr_debug("perf_evsel__read_on_cpu\n");
90 err = -1;
91 break;
92 }
93
94 expected = nr_open_calls + cpu;
95 if (evsel->counts->cpu[cpu].val != expected) {
96 pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
97 expected, cpus->map[cpu], evsel->counts->cpu[cpu].val);
98 err = -1;
99 }
100 }
101
102 perf_evsel__free_counts(evsel);
103out_close_fd:
104 perf_evsel__close_fd(evsel, 1, threads->nr);
105out_evsel_delete:
106 perf_evsel__delete(evsel);
107out_thread_map_delete:
108 thread_map__delete(threads);
109 return err;
110}