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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B9FCBC433DF for ; Fri, 31 Jul 2020 07:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F31420829 for ; Fri, 31 Jul 2020 07:47:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="f5S1EOny" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731782AbgGaHri (ORCPT ); Fri, 31 Jul 2020 03:47:38 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:41698 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727851AbgGaHri (ORCPT ); Fri, 31 Jul 2020 03:47:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596181657; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4ixNb2EBybLzWSoNGo2fASCaOj4fWf5R3chGaBD35os=; b=f5S1EOnyn3bNWpbd6J2jdtEOib6n3fSoG6LLKQR0LAxDrHPHfDQ/H3IrGeS37LRrJkApTs WBP8RQvO8BJXPXE+E3GMOdGIp48cAU1Kuox4PUz1+y9xWTax7XRqP45gkb2Kuq+rmxvXXQ qN0pUJZSvLvUkNV/Ez0/wremNAbNAoE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-422-WL5PGebtPXuGD9vBIZq2qQ-1; Fri, 31 Jul 2020 03:47:34 -0400 X-MC-Unique: WL5PGebtPXuGD9vBIZq2qQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D89191005504; Fri, 31 Jul 2020 07:47:31 +0000 (UTC) Received: from krava (unknown [10.40.194.13]) by smtp.corp.redhat.com (Postfix) with SMTP id D3A2F7C0E0; Fri, 31 Jul 2020 07:47:27 +0000 (UTC) Date: Fri, 31 Jul 2020 09:47:26 +0200 From: Jiri Olsa To: David Ahern Cc: peterz@infradead.org, Jiri Olsa , Arnaldo Carvalho de Melo , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Michael Petlan , Ian Rogers , Andi Kleen , =?iso-8859-1?Q?Genevi=E8ve?= Bastien , Wang Nan , Jeremie Galarneau Subject: Re: [PATCH 0/6] perf tools: Add wallclock time conversion support Message-ID: <20200731074726.GA1485940@krava> References: <20200730213950.1503773-1-jolsa@kernel.org> <20200730221423.GH2638@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 30, 2020 at 07:21:54PM -0600, David Ahern wrote: > On 7/30/20 4:14 PM, peterz@infradead.org wrote: > > On Thu, Jul 30, 2020 at 11:39:44PM +0200, Jiri Olsa wrote: > > > >> The patchset is adding the ability to display TOD/wallclock timestamp > >> in 'perf script' output and in 'perf data convert --to-ctf' subcommand, > >> so the converted CTF data contain TOD/wallclock timestamps. > > > > But why? Wallclock is a horrible piece of crap. Why would you want to do > > this? > > > > Same reason I brought this up 9+ years ago: userspace lives on > time-of-day, and troubleshooting is based on correlating timestamps from > multiple sources. To correlate a perf event to syslog or an application > log, we need time-of-day. yep, we have a customer that needs to compare data from multiple servers jirka