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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A8A9BCA9EAF for ; Mon, 21 Oct 2019 13:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C93321783 for ; Mon, 21 Oct 2019 13:39:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571665140; bh=0ZXePMfFtOMKmPrnY+D4JgmIn+h6ZV2J/BeW8xctlsU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OPuRT0gRCXUqoqJvn/3HteEufkyo/uL1abSIt6dXhFGTyheW0RV1n9LfSxAipK9g9 4JO6AZ+ngpWb9dYmNYT5y8jC0/Z/cX2nNK+yNVTix9uZxdi0F9bdcWBFPGb0At6Yy3 RQe6Un5TRI83Cmn6AjOG2FFf0U+VHYACArsmYTUY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729124AbfJUNi7 (ORCPT ); Mon, 21 Oct 2019 09:38:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:40400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728872AbfJUNi6 (ORCPT ); Mon, 21 Oct 2019 09:38:58 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.35.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2D73A21928; Mon, 21 Oct 2019 13:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571665137; bh=0ZXePMfFtOMKmPrnY+D4JgmIn+h6ZV2J/BeW8xctlsU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M3L5YYblANRmu3AVttvHd9DpJbb2DmUjoYqMWlIvL1dJogsdbjMtk64qbgErFuHRT QtoJ7xTCbIRI+h4RBY4te34qJkfEu+hA+rzlFJCw1CBQ85/4fgnUSCo3hNGNbhrNHN VSpwc1Y4oMKTFsVaxNf8Rx1vh5pItajVU8T0Tsy8= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Leo Yan , Alexander Shishkin , Jiri Olsa , Mark Rutland , Arnaldo Carvalho de Melo Subject: [PATCH 05/57] perf test: Avoid infinite loop for task exit case Date: Mon, 21 Oct 2019 10:37:42 -0300 Message-Id: <20191021133834.25998-6-acme@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20191021133834.25998-1-acme@kernel.org> References: <20191021133834.25998-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Leo Yan 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 19fa7cb429fd..adaff9044331 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 @@ 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; } -- 2.21.0