From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id EFC7F1F5AE for ; Fri, 21 May 2021 13:21:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233231AbhEUNWg convert rfc822-to-8bit (ORCPT ); Fri, 21 May 2021 09:22:36 -0400 Received: from elephants.elehost.com ([216.66.27.132]:20421 "EHLO elephants.elehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230391AbhEUNWe (ORCPT ); Fri, 21 May 2021 09:22:34 -0400 X-Virus-Scanned: amavisd-new at elehost.com Received: from gnash (cpe00fc8d49d843-cm00fc8d49d840.cpe.net.cable.rogers.com [173.33.197.34]) (authenticated bits=0) by elephants.elehost.com (8.15.2/8.15.2) with ESMTPSA id 14LDL30d067894 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 21 May 2021 09:21:03 -0400 (EDT) (envelope-from rsbecker@nexbridge.com) From: "Randall S. Becker" To: "'Emily Shaffer'" Cc: , "=?iso-8859-1?Q?'=C6var_Arnfj=F6r=F0_Bjarmason'?=" , "'Junio C Hamano'" , "'Jeff Hostetler'" , "'Bagas Sanjaya'" References: <20210507002908.1495061-1-emilyshaffer@google.com> <20210520210546.4129620-1-emilyshaffer@google.com> <021601d74dc0$326f6620$974e3260$@nexbridge.com> In-Reply-To: Subject: RE: [PATCH v2] tr2: log parent process name Date: Fri, 21 May 2021 09:20:57 -0400 Message-ID: <025401d74e44$25db7140$719253c0$@nexbridge.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Outlook 16.0 Content-Language: en-ca Thread-Index: AQI1+egxG3zSQittuftsBVx6FuUl5gG/TiO1Aoy/7tAC+0kMaan2WDMA Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On May 20, 2021 7:24 PM, Emily Shaffer wrote: > >On Thu, May 20, 2021 at 05:36:25PM -0400, Randall S. Becker wrote: >> >> On May 20, 2021 5:06 PM, Emily Shaffer wrote: >> >To: git@vger.kernel.org >> >Cc: Emily Shaffer ; Ævar Arnfjörð Bjarmason >> >; Junio C Hamano ; Jeff >> >Hostetler ; Bagas Sanjaya >> > >> >Subject: [PATCH v2] tr2: log parent process name >> > >> >It can be useful to tell who invoked Git - was it invoked manually by >> >a user via CLI or script? By an IDE? In some cases - like 'repo' >> >tool - we can influence the source code and set the GIT_TRACE2_PARENT_SID environment variable from the caller process. In 'repo''s >case, that parent SID is manipulated to include the string "repo", which means we can positively identify when Git was invoked by 'repo' >tool. >> >However, identifying parents that way requires both that we know >> >which tools invoke Git and that we have the ability to modify the source code of those tools. It cannot scale to keep up with the various >IDEs and wrappers which use Git, most of which we don't know about. >> >Learning which tools and wrappers invoke Git, and how, would give us insight to decide where to improve Git's usability and >performance. >> > >> >Unfortunately, there's no cross-platform reliable way to gather the >> >name of the parent process. If procfs is present, we can use that; otherwise we will need to discover the name another way. However, >the process ID should be sufficient regardless of platform. >> >> I like this idea, but there are some platforms where this is unlikely to work. NonStop, in particular, can initiate git - and I frequently do - >from a non-POSIX environment where process name is entirely different. In fact, it is something like $ABC (always beginning with a $, >which makes life very difficult for shell scripts and screws up GIT_SSH_COMMAND, but I digress). I'm going to need to plug in something >very platform-specific to make this work. getppid() always returns 1 in this situation, which is extraordinarily meaningless on the platform >and does not represent the actual parent. > >Ok. It sounds like you're saying I should be more conservative in the commit message as well as in the #ifdef scope? Do you think this >needs a reroll to made the #ifdef more aggressive, or would you rather get to it when you get to it? I'll get to it pretty quickly once it's rolled in. >It looks like the change in config.mak.uname won't affect NonStop; I think also the compat/procinfo.c is probably indicative enough of "this >stuff is for procfs" that it won't look like it *should* work for NonStop, which means that you should still get the stub for >'trace2_collect_process_info()'. But if you think the guards aren't readable enough I can try to move them around a little more. Guards are fine. There's just a lot more work to do for me. We need to make sure that the rendering of ancestor processes are generic enough not to be just pid_t through any interfaces where this is queried. In NonStop's case, char[25], should be sufficient for the short term, but I would prefer something longer, say char[128] to be safe for the future in which to stick the ancestor. To be completely unique, the ancestor is going to look like \node.$proc:sequence (where node is a 7 character name, proc is a 5 character name, and sequence is currently a long. -Randall