From patchwork Tue Jan 31 05:46:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaopeng Tan X-Patchwork-Id: 13122272 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 EC9BFC636D3 for ; Tue, 31 Jan 2023 05:50:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230340AbjAaFun (ORCPT ); Tue, 31 Jan 2023 00:50:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230344AbjAaFum (ORCPT ); Tue, 31 Jan 2023 00:50:42 -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 BE5A63B3F8; Mon, 30 Jan 2023 21:50:39 -0800 (PST) X-IronPort-AV: E=McAfee;i="6500,9779,10606"; a="84409735" X-IronPort-AV: E=Sophos;i="5.97,259,1669042800"; d="scan'208";a="84409735" Received: from unknown (HELO yto-r1.gw.nic.fujitsu.com) ([218.44.52.217]) by esa12.hc1455-7.c3s2.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2023 14:50:36 +0900 Received: from yto-m3.gw.nic.fujitsu.com (yto-nat-yto-m3.gw.nic.fujitsu.com [192.168.83.66]) by yto-r1.gw.nic.fujitsu.com (Postfix) with ESMTP id 82E4FD66A1; Tue, 31 Jan 2023 14:50:34 +0900 (JST) Received: from yto-om3.fujitsu.com (yto-om3.o.css.fujitsu.com [10.128.89.164]) by yto-m3.gw.nic.fujitsu.com (Postfix) with ESMTP id D3A27D9680; Tue, 31 Jan 2023 14:50:33 +0900 (JST) Received: from cn-r05-10.example.com (n3235113.np.ts.nmh.cs.fujitsu.co.jp [10.123.235.113]) by yto-om3.fujitsu.com (Postfix) with ESMTP id AC18740061252; Tue, 31 Jan 2023 14:50:33 +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 v6 3/5] selftests/resctrl: Flush stdout file buffer before executing fork() Date: Tue, 31 Jan 2023 14:46:53 +0900 Message-Id: <20230131054655.396270-4-tan.shaopeng@jp.fujitsu.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230131054655.396270-1-tan.shaopeng@jp.fujitsu.com> References: <20230131054655.396270-1-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]);