90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/* Copyright (c) 2021 Facebook */
|
||
|
|
#define _GNU_SOURCE
|
||
|
|
#include <pthread.h>
|
||
|
|
#include <sched.h>
|
||
|
|
#include <test_progs.h>
|
||
|
|
#include "test_perf_link.skel.h"
|
||
|
|
|
||
|
|
static void burn_cpu(void)
|
||
|
|
{
|
||
|
|
volatile int j = 0;
|
||
|
|
cpu_set_t cpu_set;
|
||
|
|
int i, err;
|
||
|
|
|
||
|
|
/* generate some branches on cpu 0 */
|
||
|
|
CPU_ZERO(&cpu_set);
|
||
|
|
CPU_SET(0, &cpu_set);
|
||
|
|
err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
|
||
|
|
ASSERT_OK(err, "set_thread_affinity");
|
||
|
|
|
||
|
|
/* spin the loop for a while (random high number) */
|
||
|
|
for (i = 0; i < 1000000; ++i)
|
||
|
|
++j;
|
||
|
|
}
|
||
|
|
|
||
|
|
void test_perf_link(void)
|
||
|
|
{
|
||
|
|
struct test_perf_link *skel = NULL;
|
||
|
|
struct perf_event_attr attr;
|
||
|
|
int pfd = -1, link_fd = -1, err;
|
||
|
|
int run_cnt_before, run_cnt_after;
|
||
|
|
struct bpf_link_info info;
|
||
|
|
__u32 info_len = sizeof(info);
|
||
|
|
|
||
|
|
/* create perf event */
|
||
|
|
memset(&attr, 0, sizeof(attr));
|
||
|
|
attr.size = sizeof(attr);
|
||
|
|
attr.type = PERF_TYPE_SOFTWARE;
|
||
|
|
attr.config = PERF_COUNT_SW_CPU_CLOCK;
|
||
|
|
attr.freq = 1;
|
||
|
|
attr.sample_freq = 4000;
|
||
|
|
pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
|
||
|
|
if (!ASSERT_GE(pfd, 0, "perf_fd"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
skel = test_perf_link__open_and_load();
|
||
|
|
if (!ASSERT_OK_PTR(skel, "skel_load"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
link_fd = bpf_link_create(bpf_program__fd(skel->progs.handler), pfd,
|
||
|
|
BPF_PERF_EVENT, NULL);
|
||
|
|
if (!ASSERT_GE(link_fd, 0, "link_fd"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
memset(&info, 0, sizeof(info));
|
||
|
|
err = bpf_obj_get_info_by_fd(link_fd, &info, &info_len);
|
||
|
|
if (!ASSERT_OK(err, "link_get_info"))
|
||
|
|
goto cleanup;
|
||
|
|
|
||
|
|
ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type");
|
||
|
|
ASSERT_GT(info.id, 0, "link_id");
|
||
|
|
ASSERT_GT(info.prog_id, 0, "link_prog_id");
|
||
|
|
|
||
|
|
/* ensure we get at least one perf_event prog execution */
|
||
|
|
burn_cpu();
|
||
|
|
ASSERT_GT(skel->bss->run_cnt, 0, "run_cnt");
|
||
|
|
|
||
|
|
/* perf_event is still active, but we close link and BPF program
|
||
|
|
* shouldn't be executed anymore
|
||
|
|
*/
|
||
|
|
close(link_fd);
|
||
|
|
link_fd = -1;
|
||
|
|
|
||
|
|
/* make sure there are no stragglers */
|
||
|
|
kern_sync_rcu();
|
||
|
|
|
||
|
|
run_cnt_before = skel->bss->run_cnt;
|
||
|
|
burn_cpu();
|
||
|
|
run_cnt_after = skel->bss->run_cnt;
|
||
|
|
|
||
|
|
ASSERT_EQ(run_cnt_before, run_cnt_after, "run_cnt_before_after");
|
||
|
|
|
||
|
|
cleanup:
|
||
|
|
if (link_fd >= 0)
|
||
|
|
close(link_fd);
|
||
|
|
if (pfd >= 0)
|
||
|
|
close(pfd);
|
||
|
|
test_perf_link__destroy(skel);
|
||
|
|
}
|