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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9EFC8CA9EB0 for ; Tue, 22 Oct 2019 00:03:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79FB720656 for ; Tue, 22 Oct 2019 00:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730569AbfJVADq (ORCPT ); Mon, 21 Oct 2019 20:03:46 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:38895 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728375AbfJVADm (ORCPT ); Mon, 21 Oct 2019 20:03:42 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iMgxT-0004G9-5V; Tue, 22 Oct 2019 01:19:27 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id D596F1C0489; Tue, 22 Oct 2019 01:19:18 +0200 (CEST) Date: Mon, 21 Oct 2019 23:19:18 -0000 From: "tip-bot2 for Leo Yan" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf test: Avoid infinite loop for task exit case Cc: Leo Yan , Alexander Shishkin , Jiri Olsa , Mark Rutland , Namhyung Kim , Arnaldo Carvalho de Melo , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <20191011091942.29841-2-leo.yan@linaro.org> References: <20191011091942.29841-2-leo.yan@linaro.org> MIME-Version: 1.0 Message-ID: <157169995839.29376.12083653777021293473.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: 791ce9c48c79210d2ffcdbe69421e7783b32921f Gitweb: https://git.kernel.org/tip/791ce9c48c79210d2ffcdbe69421e7783b32921f Author: Leo Yan AuthorDate: Fri, 11 Oct 2019 17:19:42 +08:00 Committer: Arnaldo Carvalho de Melo CommitterDate: Tue, 15 Oct 2019 08:36:22 -03:00 perf test: Avoid infinite loop for task exit case When executing the task exit testing case, perf gets stuck in an endless loop this case and doesn't return back on Arm64 Juno board. After digging into this issue, since Juno board has Arm's big.LITTLE CPUs, thus the PMUs are not compatible between the big CPUs and little CPUs. This leads to a PMU event that cannot be enabled properly when the traced task is migrated from one variant's CPU to another variant. Finally, the test case runs into infinite loop for cannot read out any event data after return from polling. Eventually, we need to work out formal solution to allow PMU events can be freely migrated from one CPU variant to another, but this is a difficult task and a different topic. This patch tries to fix the Perf test case to avoid infinite loop, when the testing detects 1000 times retrying for reading empty events, it will directly bail out and return failure. This allows the Perf tool can continue its other test cases. Signed-off-by: Leo Yan Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/20191011091942.29841-2-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/task-exit.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c index 19fa7cb..adaff90 100644 --- a/tools/perf/tests/task-exit.c +++ b/tools/perf/tests/task-exit.c @@ -54,6 +54,7 @@ int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused struct perf_cpu_map *cpus; struct perf_thread_map *threads; struct mmap *md; + int retry_count = 0; signal(SIGCHLD, sig_handler); @@ -133,6 +134,13 @@ retry: out_init: if (!exited || !nr_exit) { evlist__poll(evlist, -1); + + if (retry_count++ > 1000) { + pr_debug("Failed after retrying 1000 times\n"); + err = -1; + goto out_free_maps; + } + goto retry; }