From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40169C4320A for ; Sun, 25 Jul 2021 17:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 282EE604DC for ; Sun, 25 Jul 2021 17:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230110AbhGYQ6z convert rfc822-to-8bit (ORCPT ); Sun, 25 Jul 2021 12:58:55 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:2570 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231156AbhGYQ6y (ORCPT ); Sun, 25 Jul 2021 12:58:54 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.43/8.16.0.43) with SMTP id 16PHZmSI005412 for ; Sun, 25 Jul 2021 10:39:24 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by m0089730.ppops.net with ESMTP id 3a0ece5vgk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sun, 25 Jul 2021 10:39:23 -0700 Received: from intmgw001.25.frc3.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sun, 25 Jul 2021 10:39:22 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 919DE3D405B6; Sun, 25 Jul 2021 10:39:19 -0700 (PDT) From: Andrii Nakryiko To: , , CC: , , Peter Zijlstra Subject: [PATCH bpf-next 12/14] selftests/bpf: test low-level perf BPF link API Date: Sun, 25 Jul 2021 10:38:43 -0700 Message-ID: <20210725173845.2593626-13-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210725173845.2593626-1-andrii@kernel.org> References: <20210725173845.2593626-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: 5HY-_VMXjnJTLWjfLvKxoipzME5UP3X1 X-Proofpoint-ORIG-GUID: 5HY-_VMXjnJTLWjfLvKxoipzME5UP3X1 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-07-25_05:2021-07-23,2021-07-25 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 malwarescore=0 suspectscore=0 priorityscore=1501 phishscore=0 clxscore=1015 mlxlogscore=999 adultscore=0 lowpriorityscore=0 spamscore=0 impostorscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2107250126 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add tests utilizing low-level bpf_link_create() API to create perf BPF link. Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/prog_tests/perf_link.c | 89 +++++++++++++++++++ .../selftests/bpf/progs/test_perf_link.c | 16 ++++ 2 files changed, 105 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_link.c create mode 100644 tools/testing/selftests/bpf/progs/test_perf_link.c diff --git a/tools/testing/selftests/bpf/prog_tests/perf_link.c b/tools/testing/selftests/bpf/prog_tests/perf_link.c new file mode 100644 index 000000000000..b1abd0c46607 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_link.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#define _GNU_SOURCE +#include +#include +#include +#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); +} diff --git a/tools/testing/selftests/bpf/progs/test_perf_link.c b/tools/testing/selftests/bpf/progs/test_perf_link.c new file mode 100644 index 000000000000..c1db9fd98d0c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_perf_link.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#include "vmlinux.h" +#include +#include + +int run_cnt = 0; + +SEC("perf_event") +int handler(struct pt_regs *ctx) +{ + __sync_fetch_and_add(&run_cnt, 1); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.30.2