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e6c209da7e
Recently perf_link test started unreliably failing on libbpf CI: * https://github.com/libbpf/libbpf/actions/runs/11260672407/job/31312405473 * https://github.com/libbpf/libbpf/actions/runs/11260992334/job/31315514626 * https://github.com/libbpf/libbpf/actions/runs/11263162459/job/31320458251 Part of the test is running a dummy loop for a while and then checking for a counter incremented by the test program. Instead of waiting for an arbitrary number of loop iterations once, check for the test counter in a loop and use get_time_ns() helper to enforce a 100ms timeout. v1: https://lore.kernel.org/bpf/zuRd072x9tumn2iN4wDNs5av0nu5nekMNV4PkR-YwCT10eFFTrUtZBRkLWFbrcCe7guvLStGQlhibo8qWojCO7i2-NGajes5GYIyynexD-w=@pm.me/ Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241011153104.249800-1-ihor.solodrai@pm.me
101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2021 Facebook */
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#define _GNU_SOURCE
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#include <pthread.h>
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#include <sched.h>
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#include <test_progs.h>
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#include "testing_helpers.h"
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#include "test_perf_link.skel.h"
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#define BURN_TIMEOUT_MS 100
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#define BURN_TIMEOUT_NS BURN_TIMEOUT_MS * 1000000
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static void burn_cpu(void)
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{
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volatile int j = 0;
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cpu_set_t cpu_set;
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int i, err;
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/* generate some branches on cpu 0 */
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CPU_ZERO(&cpu_set);
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CPU_SET(0, &cpu_set);
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err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
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ASSERT_OK(err, "set_thread_affinity");
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/* spin the loop for a while (random high number) */
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for (i = 0; i < 1000000; ++i)
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++j;
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}
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/* TODO: often fails in concurrent mode */
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void serial_test_perf_link(void)
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{
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struct test_perf_link *skel = NULL;
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struct perf_event_attr attr;
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int pfd = -1, link_fd = -1, err;
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int run_cnt_before, run_cnt_after;
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struct bpf_link_info info;
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__u32 info_len = sizeof(info);
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__u64 timeout_time_ns;
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/* create perf event */
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memset(&attr, 0, sizeof(attr));
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attr.size = sizeof(attr);
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attr.type = PERF_TYPE_SOFTWARE;
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attr.config = PERF_COUNT_SW_CPU_CLOCK;
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attr.freq = 1;
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attr.sample_freq = 1000;
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pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
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if (!ASSERT_GE(pfd, 0, "perf_fd"))
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goto cleanup;
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skel = test_perf_link__open_and_load();
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if (!ASSERT_OK_PTR(skel, "skel_load"))
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goto cleanup;
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link_fd = bpf_link_create(bpf_program__fd(skel->progs.handler), pfd,
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BPF_PERF_EVENT, NULL);
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if (!ASSERT_GE(link_fd, 0, "link_fd"))
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goto cleanup;
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memset(&info, 0, sizeof(info));
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err = bpf_link_get_info_by_fd(link_fd, &info, &info_len);
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if (!ASSERT_OK(err, "link_get_info"))
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goto cleanup;
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ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type");
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ASSERT_GT(info.id, 0, "link_id");
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ASSERT_GT(info.prog_id, 0, "link_prog_id");
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/* ensure we get at least one perf_event prog execution */
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timeout_time_ns = get_time_ns() + BURN_TIMEOUT_NS;
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while (true) {
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burn_cpu();
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if (skel->bss->run_cnt > 0)
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break;
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if (!ASSERT_LT(get_time_ns(), timeout_time_ns, "run_cnt_timeout"))
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break;
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}
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/* perf_event is still active, but we close link and BPF program
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* shouldn't be executed anymore
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*/
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close(link_fd);
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link_fd = -1;
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/* make sure there are no stragglers */
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kern_sync_rcu();
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run_cnt_before = skel->bss->run_cnt;
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burn_cpu();
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run_cnt_after = skel->bss->run_cnt;
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ASSERT_EQ(run_cnt_before, run_cnt_after, "run_cnt_before_after");
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cleanup:
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if (link_fd >= 0)
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close(link_fd);
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if (pfd >= 0)
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close(pfd);
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test_perf_link__destroy(skel);
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}
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