From patchwork Thu Jul 13 13:54:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13312242 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 BD88FC001DF for ; Thu, 13 Jul 2023 13:54:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231604AbjGMNyy (ORCPT ); Thu, 13 Jul 2023 09:54:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231524AbjGMNyx (ORCPT ); Thu, 13 Jul 2023 09:54:53 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6D3181992; Thu, 13 Jul 2023 06:54:52 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B25D71576; Thu, 13 Jul 2023 06:55:34 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A829D3F73F; Thu, 13 Jul 2023 06:54:50 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , Shuah Khan , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , David Hildenbrand , Mark Brown , John Hubbard , Florent Revest , "Liam R. Howlett" Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v1 1/9] selftests: Line buffer test program's stdout Date: Thu, 13 Jul 2023 14:54:32 +0100 Message-Id: <20230713135440.3651409-2-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230713135440.3651409-1-ryan.roberts@arm.com> References: <20230713135440.3651409-1-ryan.roberts@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The selftests runner pipes the test program's stdout to tap_prefix. The presence of the pipe means that the test program sets its stdout to be fully buffered (as aposed to line buffered when directly connected to the terminal). The block buffering means that there is often content in the buffer at fork() time, which causes the output to end up duplicated. This was causing problems for mm:cow where test results were duplicated 20-30x. Solve this by using `stdbuf`, when available to force the test program to use line buffered mode. This means previously printf'ed results are flushed out of the program before any fork(). Signed-off-by: Ryan Roberts --- tools/testing/selftests/kselftest/runner.sh | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh index 1c952d1401d4..cb2b395ae296 100644 --- a/tools/testing/selftests/kselftest/runner.sh +++ b/tools/testing/selftests/kselftest/runner.sh @@ -105,8 +105,11 @@ run_one() echo "# Warning: file $TEST is missing!" echo "not ok $test_num $TEST_HDR_MSG" else + if [ -x /usr/bin/stdbuf ]; then + stdbuf="/usr/bin/stdbuf --output=L " + fi eval kselftest_cmd_args="\$${kselftest_cmd_args_ref:-}" - cmd="./$BASENAME_TEST $kselftest_cmd_args" + cmd="$stdbuf ./$BASENAME_TEST $kselftest_cmd_args" if [ ! -x "$TEST" ]; then echo "# Warning: file $TEST is not executable"