From patchwork Mon Nov 30 22:33:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 11941425 X-Patchwork-Delegate: bpf@iogearbox.net 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=unavailable 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 B0F86C71156 for ; Mon, 30 Nov 2020 22:34:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B008207BB for ; Mon, 30 Nov 2020 22:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730766AbgK3We2 convert rfc822-to-8bit (ORCPT ); Mon, 30 Nov 2020 17:34:28 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:23788 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730753AbgK3We2 (ORCPT ); Mon, 30 Nov 2020 17:34:28 -0500 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0AUMUKj9001025 for ; Mon, 30 Nov 2020 14:33:47 -0800 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3547g8fser-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 30 Nov 2020 14:33:47 -0800 Received: from intmgw002.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 30 Nov 2020 14:33:44 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 262082ECA5EA; Mon, 30 Nov 2020 14:33:40 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf 2/2] selftests/bpf: drain ringbuf samples at the end of test Date: Mon, 30 Nov 2020 14:33:36 -0800 Message-ID: <20201130223336.904192-2-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201130223336.904192-1-andrii@kernel.org> References: <20201130223336.904192-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-30_12:2020-11-30,2020-11-30 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 bulkscore=0 clxscore=1034 spamscore=0 suspectscore=8 phishscore=0 mlxscore=0 impostorscore=0 lowpriorityscore=0 malwarescore=0 mlxlogscore=977 priorityscore=1501 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011300140 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Avoid occasional test failures due to the last sample being delayed to another ring_buffer__poll() call. Instead, drain samples completely with ring_buffer__consume(). This is supposed to fix a rare and non-deterministic test failure in libbpf CI. Fixes: cb1c9ddd5525 ("selftests/bpf: Add BPF ringbuf selftests") Signed-off-by: Andrii Nakryiko --- tools/testing/selftests/bpf/prog_tests/ringbuf.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c index 1a48c6f7f54e..fddbc5db5d6a 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -220,6 +220,12 @@ void test_ringbuf(void) if (CHECK(bg_ret <= 0, "bg_ret", "epoll_wait result: %ld", bg_ret)) goto cleanup; + /* due to timing variations, there could still be non-notified + * samples, so consume them here to collect all the samples + */ + err = ring_buffer__consume(ringbuf); + CHECK(err < 0, "rb_consume", "failed: %d\b", err); + /* 3 rounds, 2 samples each */ cnt = atomic_xchg(&sample_cnt, 0); CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);