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,URIBL_BLOCKED,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 B0136ECE587 for ; Mon, 14 Oct 2019 14:11:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85AF72083B for ; Mon, 14 Oct 2019 14:11:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aSWuI0vR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732497AbfJNOLk (ORCPT ); Mon, 14 Oct 2019 10:11:40 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:36178 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732352AbfJNOLk (ORCPT ); Mon, 14 Oct 2019 10:11:40 -0400 Received: by mail-qt1-f193.google.com with SMTP id o12so25637485qtf.3 for ; Mon, 14 Oct 2019 07:11:39 -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=RPqNisl9/8QhR/3iXJbzR+QEtNfA52rxWMvfvk5p5zc=; b=aSWuI0vRPOVGeRISG8BLLKfORFzmyEYzKkJMBuq7BCRTARwtZULQ8UbJ9yX0TvNxi/ TMSJB/bPg9ODd9Im0S+l56qjZ5r6n4iQ+VhSG3HQRzpYrO2Xyi6Manupy+hEF2MJclNE slte3qL/nvtpdZUwmIU+3q/f0WKmgGPlePThjZ7ZAKyRwN4u8luWqNxFkkdM6wwpggSr pHMQrutyWjDmJW6BmMKmlXel6OsLOCPDbxTlLZDRDTdZVDLxED1u2xwIHS5/mTrdhGCQ fCsSuzSdWH/ndiomv3sW/rGi4jIyUQ52krIszORdr4+BVunABwCZVdgCQH8K+3zNZg4V AfFw== 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=RPqNisl9/8QhR/3iXJbzR+QEtNfA52rxWMvfvk5p5zc=; b=lA4+TaxyY9CW/rgdShjSXuZnqEzdTfHxsrUbIrpT2w11lGn+Rgf0yo5eCr0PLP8Occ zchJ8jwoZpRbv2FcGLIhhIHY1qwGPalkEnV0qKKoD7/VO6jrzatVXFx3qJ+Gt8Zg2x/U j5ecn0P/fLBDixpHofV4/d5OGlpwggC7+TN/4HZPv2enZn/l1HCst/FuKgdpXcuhBb9O TTbN87+eyow33hVnf4v8v/rQYdhHQvdWOzlwXR2QqWghVwJ8rPMEx0XM4LxXkg09YoBL TSAq/28AMo6D6gf9Q9sM4ToPGYJKPyyfnJ9DexRiEel6u+Lc3siRQu7aJ57xkA87Es7d /7iQ== X-Gm-Message-State: APjAAAUuAMmfJIuYvkwwRDsZ45fTR2XocCLxJV32XQUV0LNZtBvU9h8Z a7c/GCnmCtug8i6ES6O9Jlw= X-Google-Smtp-Source: APXvYqwbYzyiJbi1P52sPo+JYT0X6U0C5f4qZBL7L0+I2GaNY9kSzIfSOlHemPV8pCGZ3TZGVZUdtg== X-Received: by 2002:ac8:5243:: with SMTP id y3mr13900733qtn.74.1571062299155; Mon, 14 Oct 2019 07:11:39 -0700 (PDT) Received: from quaco.ghostprotocols.net ([179.97.35.50]) by smtp.gmail.com with ESMTPSA id w73sm8581241qkb.111.2019.10.14.07.11.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Oct 2019 07:11:38 -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 6C8B14DD66; Mon, 14 Oct 2019 11:11:36 -0300 (-03) Date: Mon, 14 Oct 2019 11:11:36 -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: <20191014141136.GD19627@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. > > 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. Thanks, applied. - Arnaldo > 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