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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 0611EC169C4 for ; Mon, 11 Feb 2019 18:53:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D129221B25 for ; Mon, 11 Feb 2019 18:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731840AbfBKSxL (ORCPT ); Mon, 11 Feb 2019 13:53:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41304 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726228AbfBKSxK (ORCPT ); Mon, 11 Feb 2019 13:53:10 -0500 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 mx1.redhat.com (Postfix) with ESMTPS id 08A12C01DE05; Mon, 11 Feb 2019 18:53:10 +0000 (UTC) Received: from krava (ovpn-204-173.brq.redhat.com [10.40.204.173]) by smtp.corp.redhat.com (Postfix) with SMTP id 08E6160A9A; Mon, 11 Feb 2019 18:53:06 +0000 (UTC) Date: Mon, 11 Feb 2019 19:53:06 +0100 From: Jiri Olsa To: Stephane Eranian Cc: Arnaldo Carvalho de Melo , Alexey Budankov , Jiri Olsa , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Adrian Hunter , Andi Kleen Subject: Re: [RFC/PATCH 00/14] perf record: Add support to store data in directory Message-ID: <20190211185306.GD5046@krava> References: <6bf24b7d-2bd3-8091-cf49-363c91e4e864@linux.intel.com> <20190204114144.GC18141@krava> <20190204192721.GI5593@kernel.org> <20190204202818.GC4794@krava> <20190205133727.GF4794@krava> <20190211101957.GB14253@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 11 Feb 2019 18:53:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 11, 2019 at 10:34:16AM -0800, Stephane Eranian wrote: > Jiri, > > On Mon, Feb 11, 2019 at 2:20 AM Jiri Olsa wrote: > > > > On Tue, Feb 05, 2019 at 02:37:27PM +0100, Jiri Olsa wrote: > > > On Mon, Feb 04, 2019 at 02:44:37PM -0800, Stephane Eranian wrote: > > > > Jiri, > > > > > > > > While you're looking at the output format, I think it would be good > > > > time to simplify the code handling perf.data file. > > > > Today, perf record can emit in two formats: file mode or pipe mode. > > > > This adds complexity in the code and > > > > is error prone as the file mode path is tested more than the pipe mode > > > > path. We have run into multiple issues with > > > > the pipe mode in recent years. There is no real reason why we need to > > > > maintain two formats. If I recall, the pipe format > > > > was introduced because on pipes you cannot lseek to update the headers > > > > and therefore some of the information present as tables > > > > updated on the fly needed to be generated as pseudo records by the > > > > tool. I believe that the pipe format covers all the needs and could > > > > supersede the file mode format. That would simplify code in perf > > > > record and eliminate the risk of errors when new headers > > > > are introduced. > > > > > > yep, I think we have almost all the features covered for pipe mode, > > > and we have all necessary events to describe events features > > > > > > so with some effort we could switch off the superfluos file header > > > and use only events to describe events ;-) make sense, I'll check > > > on it > > > > so following features are not synthesized: > > > > FEAT_OPN(TRACING_DATA, tracing_data, false), > > FEAT_OPN(BUILD_ID, build_id, false), > > FEAT_OPN(BRANCH_STACK, branch_stack, false), > > FEAT_OPN(AUXTRACE, auxtrace, false), > > FEAT_OPN(STAT, stat, false), > > FEAT_OPN(CACHE, cache, true), > > > What do you need for BRANCH_STACK? nothing, I think it's just the flag > > > I think all could be added and worked around with exception > > of BUILD_ID, which we store at the end (after processing > > all data) and we need it early in the report phase > > > Buildids are injected after the fact via perf inject when in pipe mode. > > > maybe it's time to re-think that buildid -> mmap event > > association again, because it's pain in current implementation > > as well > > > Sure, but what do you propose? > this: > > looks like bpf code is actualy getting build ids and storing > > it for the callchains in kernel.. we can check if we can do > > something similar for mmap events > > > > jirka jirka