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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D724AC47404 for ; Fri, 11 Oct 2019 14:38:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA81F20673 for ; Fri, 11 Oct 2019 14:38:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qnAwrnQg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727091AbfJKOiI (ORCPT ); Fri, 11 Oct 2019 10:38:08 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:38632 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726953AbfJKOiI (ORCPT ); Fri, 11 Oct 2019 10:38:08 -0400 Received: by mail-qt1-f193.google.com with SMTP id j31so14177969qta.5 for ; Fri, 11 Oct 2019 07:38:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=kC6tRrQSq+U5wVR80DlQ4qp9ZXmbi64kvO32OghQf7A=; b=qnAwrnQgcmLQ+Fk2BGmhAB4jF/lr9XuLxBbmiAg+o+3IrZnIBzJDWoZXEPD69eWYue XjEoU2s6KzprJUWFnNiJh9IPBKiW9iyMFrAnqgMHT7QTQ1zOnezSwKU7tjn8Yv9aT8CR 3rA3qcy7Gm94hNqzWPFL5zU+TSYoioG0329Jw8V6jS5W8SSQCmiCuSGSHF9BoVKFok0O gaDN4ZFd2lgYm+tYeOSCvo01SsSOsNvaL7SNyybB4HS18sZ12xuJ3dwoEBb3Nus9QiKD scsxioexObiAewHmoi0H9wIb9Q0f9owbsSTjqf7S2RGLwoSP2uEY4e3d8pcGY4llqhsU svCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=kC6tRrQSq+U5wVR80DlQ4qp9ZXmbi64kvO32OghQf7A=; b=f5VSDHhOxLl5sJMazTRdqoxZMX26YhI8MSHSdJScMusbFlm0WC4gps89Q2dog26s44 OjMWLH5FzD+rVXrj3hcGBKH17rk7BLRbMmveiLYOtDUPzTSN5cbh80CwxxhfsMd0g9sC 0Gl12xeQlPErKV0eMwvW8/Z2yuTfwzqfxFQCkVJoijVFAvl3frguzAnMXdDBLqIYn2Ip fRaO7AayqI+uOwhQLvY8W3ckteLG+/dIuOdADNx/3OZDobhnaBuXEl2UZsS0DrwEbZ9O hpns+OyuhA9lQfJdGVA+fwUwPaxHW6xGDdmuQsixbfXaj2X6AhGwKKIHUJyCbRmy3F5T CruA== X-Gm-Message-State: APjAAAUZAatbdKhr2XRdLXOJvF4Or7yx7IYaO645ExB/k9g5w+zC1dU7 F/cAIyrXPoL6yFv8C9Qz9xE= X-Google-Smtp-Source: APXvYqyeGe5VIm8U6UK/rwgLW9tmWUNSy4P2MQBlBs3d22PbmkGcYAs5uQi9Fa3ndHHdeBKrsb1AMQ== X-Received: by 2002:a05:6214:18f:: with SMTP id q15mr16177473qvr.129.1570804687085; Fri, 11 Oct 2019 07:38:07 -0700 (PDT) Received: from quaco.ghostprotocols.net ([179.97.35.50]) by smtp.gmail.com with ESMTPSA id c14sm4690836qta.80.2019.10.11.07.38.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Oct 2019 07:38:05 -0700 (PDT) From: Arnaldo Carvalho de Melo X-Google-Original-From: Arnaldo Carvalho de Melo Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 83F1E4DD66; Fri, 11 Oct 2019 11:38:03 -0300 (-03) Date: Fri, 11 Oct 2019 11:38:03 -0300 To: Leo Yan Cc: Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 2/2] perf test: Avoid infinite loop for task exit case Message-ID: <20191011143803.GB32176@kernel.org> References: <20191011091942.29841-1-leo.yan@linaro.org> <20191011091942.29841-2-leo.yan@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191011091942.29841-2-leo.yan@linaro.org> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Oct 11, 2019 at 05:19:42PM +0800, Leo Yan escreveu: > When execute task exit testing case, Perf tool stucks in this case and > doesn't return back on Arm64 Juno board. > > After dig 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 PMU event 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. Thanks, I'll go over this after I finish the current pull request, - Arnaldo > 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 > --- > 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 ca0a6ca43b13..d85c9f608564 100644 > --- a/tools/perf/tests/task-exit.c > +++ b/tools/perf/tests/task-exit.c > @@ -53,6 +53,7 @@ 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); > > @@ -132,6 +133,13 @@ int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused > 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; > } > > -- > 2.17.1 -- - Arnaldo