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-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 AC4941F66E for ; Wed, 2 Sep 2020 17:49:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726521AbgIBRtt (ORCPT ); Wed, 2 Sep 2020 13:49:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726247AbgIBRts (ORCPT ); Wed, 2 Sep 2020 13:49:48 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD344C061244 for ; Wed, 2 Sep 2020 10:49:47 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id g6so30214pfi.1 for ; Wed, 02 Sep 2020 10:49:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=MrJDuUDrdFNscSsuXx1QvvG/ZTJdBSwjpjjY/vvgIAc=; b=CjIISTnTUtF70l9b8hlL3dvyuMT4j1zEZNnvLJtXmwhokBb6DA7Pj/wZHjiVCGjLw5 UwcIIc84m9KvFSuV6RqOlm/RPQCjcL4v6RX0yZIzPGKme/C2hDUgLOetyEj4oMhH42N+ SzroNeD+DRon+1B4CrYBEDgkkUTzAne4avHuVRxkh6RCAjYOAvdIA/4O2Xo9aUUQ8iiO ywX3G0/x9c+j8ZWdc3h4Uoog9PHjZP9Ka+X23GGL6F0VLdFcZjqT9saiUnNIPkwpoO4t 85RUNS+YhlFgjdIlU25SoEnOXrwX+8ZTGRQWHuX35QlVy5I9qrNUR7j2m+GTeCO3cBga FQXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=MrJDuUDrdFNscSsuXx1QvvG/ZTJdBSwjpjjY/vvgIAc=; b=N7OCDKxXWOmrtvcgvM+GXnjv2jZlIefG4wW7opPTe+LgZtXamIelBXKsf341of0kdC ki7euK/xNlCLJBy20SbplQ8XlQO8DW4h7JRPvGVDF0ZiUurF7thyRBLGyn+4wvQco7mO FvJSEPaTHqIbMy11mx9kszU53YGSfYc9M3468G3cOF/9j8fHQP8gwSDmtkaaseAE2MFQ iO5MvZZg3CPwGTaeTN7g5z4+V1yefdfIYgUUFJQcMQNTgyLn2lm5Qh7LpRHw7zvLAMLs h9ra2e+00Fj71uS8qP59sVAlENvt8Nfkmvs+SpZDKJ7ep2FaeG+yy2M1aO0bUyda8HAW 5HiA== X-Gm-Message-State: AOAM530c8seWmyfgqc/Mfv7NE4MST0M1LG4K+nqLltOBkvXDQoo7ZPN8 WsLPw/H+eoI/8v8vacRTPetno0UYKOA+QkeHUzm8 X-Google-Smtp-Source: ABdhPJyPQp7mKbW3EznRx5N3/cftmsN6ZQuMibjhYO7opOmAfxLDlQ/m8haoykuSewa9jN0w6pfSfSp5ypPTKf/USf5T X-Received: from twelve4.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:18d]) (user=jonathantanmy job=sendgmr) by 2002:a17:902:7689:b029:cf:85aa:69f4 with SMTP id m9-20020a1709027689b02900cf85aa69f4mr4547528pll.1.1599068986893; Wed, 02 Sep 2020 10:49:46 -0700 (PDT) Date: Wed, 2 Sep 2020 10:49:39 -0700 In-Reply-To: Message-Id: <20200902174939.3391882-1-jonathantanmy@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.402.g5ffc5be6b7-goog Subject: Re: [PATCH] RFC: refs: add GIT_DEBUG_REFS debugging mechanism From: Jonathan Tan To: gitgitgadget@gmail.com Cc: git@vger.kernel.org, hanwenn@gmail.com, hanwen@google.com, git@jeffhostetler.com, stolee@gmail.com, Jonathan Tan Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org > This should be integrated with the trace2 sub-system, and I would appreciate > pointers on how to start. The trace2 subsystem seems to be designed to detect errors coarsely (e.g. by looking at process invocations) and log timings. It currently doesn't seem to be made for this kind of fine debugging information - and perhaps this is by design, because such logging information would not be useful to most users and would just clutter up the logs. But I think there is a place for this in Git - in particular, we have packet tracing (GIT_TRACE_PACKET), and this has been useful both in automated tests (t/????-*.sh) and in manual tests. Ref backend tracing seems to be similar. But this would be best if we had an additional option that could control whether ref backend tracing was on or off, independent from other things like the trace2 target. Is the plan to migrate all usages of "trace" to "trace2" or for both to exist simultaneously? If the latter, then ref backend tracing could just use "trace", but if the former, we'd have to designing this additional option.