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// 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;
}
/* TODO: often fails in concurrent mode */
void serial_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);
}
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