From nobody Tue Feb 10 04:29:37 2026 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 D1F72C77B7F for ; Sat, 13 May 2023 07:40:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230316AbjEMHkZ (ORCPT ); Sat, 13 May 2023 03:40:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbjEMHkV (ORCPT ); Sat, 13 May 2023 03:40:21 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A70135B5; Sat, 13 May 2023 00:40:17 -0700 (PDT) Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QJHVl3wxQz18LQJ; Sat, 13 May 2023 15:35:59 +0800 (CST) Received: from M910t.huawei.com (10.110.54.157) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Sat, 13 May 2023 15:40:13 +0800 From: Changbin Du To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo CC: Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , , , Changbin Du Subject: [PATCH] perf: ftrace: flush output after each writing Date: Sat, 13 May 2023 15:40:00 +0800 Message-ID: <20230513074000.733550-1-changbin.du@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.110.54.157] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The pager will result stdout in full buffering mode instead of line buffering. We need to make the trace visible timely. Signed-off-by: Changbin Du --- tools/perf/builtin-ftrace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 810e3376c7d6..ad2a9ae041f6 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -650,6 +650,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace) break; if (fwrite(buf, n, 1, stdout) !=3D 1) break; + /* flush output since stdout is in full buffering mode due to pager */ + fflush(stdout); } } =20 --=20 2.25.1