From patchwork Mon Jan 23 08:32:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Naveen N. Rao" X-Patchwork-Id: 13111759 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CF3FC54EAA for ; Mon, 23 Jan 2023 08:33:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231502AbjAWIdA (ORCPT ); Mon, 23 Jan 2023 03:33:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230107AbjAWIdA (ORCPT ); Mon, 23 Jan 2023 03:33:00 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A18E1CAFC; Mon, 23 Jan 2023 00:32:58 -0800 (PST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30N7MpYB005165; Mon, 23 Jan 2023 08:32:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=vTAjVjUD2Bx8RbzMfrZSM1izm0jUPvkT5n1cgO3yShM=; b=adw36Si9MumagBZ/6Ml+Xxz4gUVhUl9dXP9OgkP03pfBl4Zkge3bhIteH6C/H6TDaGR4 MZablMRy2v5TQdSof12JjOB44+84XgNQFowsig13IYGvoKyNlPGXpddZogZViTGuzR4t AV7lfEpOi+MyNMbgah4gj+CYKhtuihduvyGDN9YnVGKkUobg7xOPurlNvl9QarLbVE+3 U/GLfxrfC0lQTJXXVITWFGfM3mGfVUHZYaF52sKRJIM1huc+S7F4/HwiZ5qtb2i7yPr4 Xk3nry5pxvBMYONYi1w0IsUZJ/p1/4Cal5gUKeH/LaZZ3qCdNq8Umij9HvM/AcFqno9d jw== Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3n9nsyhcdt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Jan 2023 08:32:49 +0000 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 30N5Uh6d010402; Mon, 23 Jan 2023 08:32:47 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma03ams.nl.ibm.com (PPS) with ESMTPS id 3n87p6j12w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Jan 2023 08:32:47 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 30N8WhdG22872482 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 23 Jan 2023 08:32:44 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C67F620040; Mon, 23 Jan 2023 08:32:43 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 98FAE20043; Mon, 23 Jan 2023 08:32:42 +0000 (GMT) Received: from li-NotSettable.ibm.com (unknown [9.124.31.208]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 23 Jan 2023 08:32:42 +0000 (GMT) From: "Naveen N. Rao" To: Arnaldo Carvalho de Melo Cc: Disha Goel , Kajol Jain , , , Subject: [PATCH] perf test: Switch basic bpf filtering test to use syscall tracepoint Date: Mon, 23 Jan 2023 14:02:24 +0530 Message-Id: <20230123083224.276404-1-naveen.n.rao@linux.vnet.ibm.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: dWMEpBmkTrARYmSKd-G7m-vXpKRLgCki X-Proofpoint-ORIG-GUID: dWMEpBmkTrARYmSKd-G7m-vXpKRLgCki X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-01-23_05,2023-01-20_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 spamscore=0 impostorscore=0 mlxscore=0 bulkscore=0 malwarescore=0 adultscore=0 mlxlogscore=999 phishscore=0 clxscore=1011 lowpriorityscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301230080 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org BPF filtering tests can sometime fail. Running the test in verbose mode shows the following: $ sudo perf test 42 42: BPF filter : 42.1: Basic BPF filtering : FAILED! 42.2: BPF pinning : Skip 42.3: BPF prologue generation : Skip $ perf --version perf version 4.18.0-425.3.1.el8.ppc64le $ sudo perf test -v 42 42: BPF filter : 42.1: Basic BPF filtering : --- start --- test child forked, pid 711060 ... bpf: config 'func=do_epoll_wait' is ok Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/lib/modules/4.18.0-425.3.1.el8.ppc64le/vmlinux for symbols Open Debuginfo file: /usr/lib/debug/.build-id/81/56f5a07f92ccb62c5600ba0e4aacfb5f3a7534.debug Try to find probe point from debuginfo. Matched function: do_epoll_wait [4ef8cb0] found inline addr: 0xc00000000061dbe4 Probe point found: __se_compat_sys_epoll_pwait+196 found inline addr: 0xc00000000061d9f4 Probe point found: __se_sys_epoll_pwait+196 found inline addr: 0xc00000000061d824 Probe point found: __se_sys_epoll_wait+36 Found 3 probe_trace_events. Opening /sys/kernel/tracing//kprobe_events write=1 ... BPF filter result incorrect, expected 56, got 56 samples test child finished with -1 ---- end ---- BPF filter subtest 1: FAILED! The statement above about the result being incorrect looks weird, and it is due to that particular perf build missing commit 3e11300cdfd5f1 ("perf test: Fix bpf test sample mismatch reporting"). In reality, due to commit 4b04e0decd2518 ("perf test: Fix basic bpf filtering test"), perf expects there to be 56*3 samples. However, the number of samples we receive is going to be dependent on where the probes are installed, which is dependent on where do_epoll_wait gets inlined. On s390x, it looks like probes at all the inlined locations are hit. But, that is not the case on ppc64le. Fix this by switching the test to instead use the syscall tracepoint. This ensures that we will only ever install a single event enabling us to reliably determine the sample count. Reported-by: Disha Goel Signed-off-by: Naveen N. Rao Reviewed-by: Kajol Jain --- tools/perf/tests/bpf-script-example.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: 5670ebf54bd26482f57a094c53bdc562c106e0a9 diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c index 7981c69ed1b456..b638cc99d5ae56 100644 --- a/tools/perf/tests/bpf-script-example.c +++ b/tools/perf/tests/bpf-script-example.c @@ -43,7 +43,7 @@ struct { __type(value, int); } flip_table SEC(".maps"); -SEC("func=do_epoll_wait") +SEC("syscalls:sys_enter_epoll_pwait") int bpf_func__SyS_epoll_pwait(void *ctx) { int ind =0;