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=-11.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=no 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 6DEA0C433E0 for ; Thu, 18 Jun 2020 22:16:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B46420786 for ; Thu, 18 Jun 2020 22:16:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="TWiGtPnX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731764AbgFRWQb (ORCPT ); Thu, 18 Jun 2020 18:16:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729889AbgFRWQ1 (ORCPT ); Thu, 18 Jun 2020 18:16:27 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9146C0613EE for ; Thu, 18 Jun 2020 15:16:27 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id b135so7863448yba.11 for ; Thu, 18 Jun 2020 15:16:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=wMNnopaSonqA5zRbMSt0/GvIJJ9qEKFy+7LLVQ7GDPc=; b=TWiGtPnX5kmaogbttxbe82Mz3iBJGTAqb1uzA2JhBks/9qVqXtvy6eP9BCuOE9vLL7 oaSpzJ0JpgG/ntxAtjY7ZBrUDpEjeiXNwVeWfbMwdVHHQXAidzuFxQyjqry053LHE81q XbNHMPL/TK8hL+pGgcoHdlb/yEUstu+0Nr7yitO+JjIjD3KxzGUndBjNc3WdCiecCASY /SycHzycdz9E+TOqt/aaxVgEXuVlq9cFuw4qe66sMNvRnI86gxrEassn7lQF1BqC/ioW s3QMN3poclP1HYx1N75nZeLbEJMx/JCRMrdafr1bK0Z2FFYzkoGbNU0Z4Qusd5+IO19C kevg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=wMNnopaSonqA5zRbMSt0/GvIJJ9qEKFy+7LLVQ7GDPc=; b=eVvblSsNhd8gg45WiJIUg1dX31kGUdEio/1RYHnMqbcOINpePiL6y+4+Ar4JuZ0Uyy XvqzXyDAGwe64yU2aZnEE/WGsR8zJIEIB02lGslTlCHh/nFkLBQhhp1EgMLeo4MEc1FK UCYijOsaV1a5Js0RUGa45gzFmaVSjT/k5i59dtlhf3n6SxDSbnRveNvafT480RU06HTD NDQGbWfbrDj62/NurPMEo+jhfV0rqnyzqS5+Rp92TmAY1SL5cH/wVbp/tKTcgf44CrrD W/2Ya1ggtLh3l8E2khM56AUFYyMvqimdlglyXeTkc+NUKacCbmg7Iu1qRoxSEvBnB4BR MURg== X-Gm-Message-State: AOAM533nlF5+q0Vh8if1waIlUQMGr4C+nQeE3OWWOIDGCN6+LbLg3XCJ D7XQJ7STR+dxqMP/V8TXehsIpYI279Y= X-Google-Smtp-Source: ABdhPJzfrP9kOj0Vvbg+A1B4/d9Ko8ZRmuwbRcM5xJpeSqqp3FRN4zZsBDm7xxC8JhErvGzZlTHdV+isYgY= X-Received: by 2002:a25:3bca:: with SMTP id i193mr1220879yba.327.1592518586941; Thu, 18 Jun 2020 15:16:26 -0700 (PDT) Date: Thu, 18 Jun 2020 15:15:39 -0700 Message-Id: <20200618221541.247643-1-korben@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.27.0.111.gc72c7da667-goog Subject: [PATCH 0/2] force absolute timestamp trace option From: Korben Rusek To: Steven Rostedt , Ingo Molnar , Jonathan Corbet Cc: Peter Shier , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, jbehmer@google.com, franksie@google.com, Korben Rusek Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Normally a data event includes the delta time between itself and the previous data event. But if a write interrupts another write then the event cannot check the timestamp of the previous event and so it uses a delta of 0. Adds a new trace option: force-abs-timestamp. When this is on each event is proceeded by an absolute timestamp event. This follows from a discussion between jbehmer@google.com and Steven Rostedt found here: https://lkml.org/lkml/2019/5/24/710 Korben Rusek (2): Add force-abs-timestamp trace option. tests for absolute timestamp Documentation/trace/ftrace.rst | 5 + kernel/trace/trace.c | 4 + kernel/trace/trace.h | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/timestamp/Makefile | 25 +++ tools/testing/selftests/timestamp/abs-test.sh | 156 ++++++++++++++ .../selftests/timestamp/abs-timestamp.c | 198 ++++++++++++++++++ 7 files changed, 390 insertions(+) create mode 100644 tools/testing/selftests/timestamp/Makefile create mode 100644 tools/testing/selftests/timestamp/abs-test.sh create mode 100644 tools/testing/selftests/timestamp/abs-timestamp.c -- 2.27.0.290.gba653c62da-goog