From patchwork Thu Nov 17 01:05:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaopeng Tan X-Patchwork-Id: 625901 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 9652AC43217 for ; Thu, 17 Nov 2022 01:11:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238592AbiKQBLr (ORCPT ); Wed, 16 Nov 2022 20:11:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234493AbiKQBLl (ORCPT ); Wed, 16 Nov 2022 20:11:41 -0500 Received: from esa12.hc1455-7.c3s2.iphmx.com (esa12.hc1455-7.c3s2.iphmx.com [139.138.37.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7EE91DF11; Wed, 16 Nov 2022 17:11:39 -0800 (PST) X-IronPort-AV: E=McAfee;i="6500,9779,10533"; a="75835688" X-IronPort-AV: E=Sophos;i="5.96,169,1665414000"; d="scan'208";a="75835688" Received: from unknown (HELO yto-r2.gw.nic.fujitsu.com) ([218.44.52.218]) by esa12.hc1455-7.c3s2.iphmx.com with ESMTP; 17 Nov 2022 10:11:36 +0900 Received: from yto-m3.gw.nic.fujitsu.com (yto-nat-yto-m3.gw.nic.fujitsu.com [192.168.83.66]) by yto-r2.gw.nic.fujitsu.com (Postfix) with ESMTP id C8AE5C68E4; Thu, 17 Nov 2022 10:11:35 +0900 (JST) Received: from oym-om4.fujitsu.com (oym-om4.o.css.fujitsu.com [10.85.58.164]) by yto-m3.gw.nic.fujitsu.com (Postfix) with ESMTP id 2D62CD9693; Thu, 17 Nov 2022 10:11:35 +0900 (JST) Received: from cn-r05-10.example.com (n3235113.np.ts.nmh.cs.fujitsu.co.jp [10.123.235.113]) by oym-om4.fujitsu.com (Postfix) with ESMTP id 0A7C540089710; Thu, 17 Nov 2022 10:11:35 +0900 (JST) From: Shaopeng Tan To: Fenghua Yu , Reinette Chatre , Shuah Khan Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, tan.shaopeng@jp.fujitsu.com, Shuah Khan Subject: [PATCH v4 3/5] selftests/resctrl: Flush stdout file buffer before executing fork() Date: Thu, 17 Nov 2022 10:05:39 +0900 Message-Id: <20221117010541.1014481-4-tan.shaopeng@jp.fujitsu.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20221117010541.1014481-1-tan.shaopeng@jp.fujitsu.com> References: <20221117010541.1014481-1-tan.shaopeng@jp.fujitsu.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org When a process has buffered output, a child process created by fork() will also copy buffered output. When using kselftest framework, the output (resctrl test result message) will be printed multiple times. Add fflush() to flush out the buffered output before executing fork(). Reviewed-by: Shuah Khan Reviewed-by: Reinette Chatre Signed-off-by: Shaopeng Tan --- tools/testing/selftests/resctrl/cat_test.c | 1 + tools/testing/selftests/resctrl/resctrl_val.c | 1 + tools/testing/selftests/resctrl/resctrlfs.c | 1 + 3 files changed, 3 insertions(+) diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index 1c5e90c63254..6a8306b0a109 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -167,6 +167,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) return errno; } + fflush(stdout); bm_pid = fork(); /* Set param values for child thread which will be allocated bitmask diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c index b32b96356ec7..6948843bf995 100644 --- a/tools/testing/selftests/resctrl/resctrl_val.c +++ b/tools/testing/selftests/resctrl/resctrl_val.c @@ -629,6 +629,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param) * Fork to start benchmark, save child's pid so that it can be killed * when needed */ + fflush(stdout); bm_pid = fork(); if (bm_pid == -1) { perror("# Unable to fork"); diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 8546bc9f1786..d95688298469 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -678,6 +678,7 @@ int filter_dmesg(void) perror("pipe"); return ret; } + fflush(stdout); pid = fork(); if (pid == 0) { close(pipefds[0]);