91 lines · c
1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2021 Facebook */3#define _GNU_SOURCE4#include <pthread.h>5#include <sched.h>6#include <test_progs.h>7#include "test_perf_link.skel.h"8 9static void burn_cpu(void)10{11 volatile int j = 0;12 cpu_set_t cpu_set;13 int i, err;14 15 /* generate some branches on cpu 0 */16 CPU_ZERO(&cpu_set);17 CPU_SET(0, &cpu_set);18 err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);19 ASSERT_OK(err, "set_thread_affinity");20 21 /* spin the loop for a while (random high number) */22 for (i = 0; i < 1000000; ++i)23 ++j;24}25 26/* TODO: often fails in concurrent mode */27void serial_test_perf_link(void)28{29 struct test_perf_link *skel = NULL;30 struct perf_event_attr attr;31 int pfd = -1, link_fd = -1, err;32 int run_cnt_before, run_cnt_after;33 struct bpf_link_info info;34 __u32 info_len = sizeof(info);35 36 /* create perf event */37 memset(&attr, 0, sizeof(attr));38 attr.size = sizeof(attr);39 attr.type = PERF_TYPE_SOFTWARE;40 attr.config = PERF_COUNT_SW_CPU_CLOCK;41 attr.freq = 1;42 attr.sample_freq = 1000;43 pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);44 if (!ASSERT_GE(pfd, 0, "perf_fd"))45 goto cleanup;46 47 skel = test_perf_link__open_and_load();48 if (!ASSERT_OK_PTR(skel, "skel_load"))49 goto cleanup;50 51 link_fd = bpf_link_create(bpf_program__fd(skel->progs.handler), pfd,52 BPF_PERF_EVENT, NULL);53 if (!ASSERT_GE(link_fd, 0, "link_fd"))54 goto cleanup;55 56 memset(&info, 0, sizeof(info));57 err = bpf_link_get_info_by_fd(link_fd, &info, &info_len);58 if (!ASSERT_OK(err, "link_get_info"))59 goto cleanup;60 61 ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type");62 ASSERT_GT(info.id, 0, "link_id");63 ASSERT_GT(info.prog_id, 0, "link_prog_id");64 65 /* ensure we get at least one perf_event prog execution */66 burn_cpu();67 ASSERT_GT(skel->bss->run_cnt, 0, "run_cnt");68 69 /* perf_event is still active, but we close link and BPF program70 * shouldn't be executed anymore71 */72 close(link_fd);73 link_fd = -1;74 75 /* make sure there are no stragglers */76 kern_sync_rcu();77 78 run_cnt_before = skel->bss->run_cnt;79 burn_cpu();80 run_cnt_after = skel->bss->run_cnt;81 82 ASSERT_EQ(run_cnt_before, run_cnt_after, "run_cnt_before_after");83 84cleanup:85 if (link_fd >= 0)86 close(link_fd);87 if (pfd >= 0)88 close(pfd);89 test_perf_link__destroy(skel);90}91