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=-13.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 D8640C433E0 for ; Wed, 8 Jul 2020 23:57:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9C8620659 for ; Wed, 8 Jul 2020 23:57:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Dlk1Cw4L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726121AbgGHX50 (ORCPT ); Wed, 8 Jul 2020 19:57:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbgGHX5Z (ORCPT ); Wed, 8 Jul 2020 19:57:25 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88C29C061A0B for ; Wed, 8 Jul 2020 16:57:25 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id j19so111310pgm.11 for ; Wed, 08 Jul 2020 16:57:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=qoTwDgBZCWxJTz4I1SYUGCkpe2+y00B5btlMYuLIP5Y=; b=Dlk1Cw4LxVy9hcd4YB7dLAfbas+hQwVP6Um3gXlpi/pJZdPOOfzYE1BK4oi2RirYeW hhiZhcm+uRLjrlRhrJaUA3WlirtJRgowmb8NeOhdiMbFrgwrXOgJzVzq/JD4mVpuCxBz TYKJok7tLSVOrjHc1lsNh8PPlt6Le9e4PozDdSrvrw9UjeTvXBKn7aKxnL0S/WdaaciJ 3mwIhWB1BzSZwUtDSKkfi3LyBTFjkWIL9jaPLt1J7hwgiutw3JPrcT77OS/inB7Xle+Y 65YaIEjBKs4hq+0/J+WaXfMiiGyTahCqYtxUi/c4NJdWyv2K5E65KmD+8AWJprHYFWbA pDFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=qoTwDgBZCWxJTz4I1SYUGCkpe2+y00B5btlMYuLIP5Y=; b=CsAv3nt3UYCrS/eBU3W0JikyKfrYROT4A8DNgSZsgICE8qwa3ZKN5LbtTIgxorKzGJ 7OMdr+6f/hilRSFJlFXDFlI1hfx+pRkX7dcax/f2G+M2MNt5PBVFc2XyXxE+tSWQBmW+ kN2OIAXrJVQRbYrl5HUh94RHhHG8/3Or5hQXcht07ab5sCzVIezWljCCiDq1EkrLA2bl rzbsDSIhwerZZ9ZY/+O/qeRb3U98b8CURYYLqVYSzioklnKIRu1zvlPh6G2bCCe0t35W oci1y2xNbA0m/dDLLoh5jrKCzparA5qhqZcOC7uWzmesC4vn/JYCIG92IdgkPoCSJN0+ 8+2A== X-Gm-Message-State: AOAM530aea7HcnV4lNtsS5GBZWgsAd+eXScGlGhB7eBnyvi6YEdBELh4 NyYz69rSj3dhfePfD/MWJE+X0A== X-Google-Smtp-Source: ABdhPJyOu+CTlk9H4csNBGFfAXfNx1VnvjzNetX5DxDksEH9iv5bCZerJgWm/ZXPnV9dU35/Zf1+Aw== X-Received: by 2002:a62:8c54:: with SMTP id m81mr51974959pfd.215.1594252644851; Wed, 08 Jul 2020 16:57:24 -0700 (PDT) Received: from google.com ([2620:15c:2ce:0:1ea0:b8ff:fe77:f690]) by smtp.gmail.com with ESMTPSA id e5sm547225pjv.18.2020.07.08.16.57.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jul 2020 16:57:24 -0700 (PDT) Date: Wed, 8 Jul 2020 16:57:19 -0700 From: Emily Shaffer To: Derrick Stolee via GitGitGadget Cc: git@vger.kernel.org, Johannes.Schindelin@gmx.de, sandals@crustytoothpaste.net, steadmon@google.com, jrnieder@gmail.com, peff@peff.net, congdanhqx@gmail.com, phillip.wood123@gmail.com, Derrick Stolee Subject: Re: [PATCH 00/21] Maintenance builtin, allowing 'gc --auto' customization Message-ID: <20200708235719.GA3189386@google.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, Jul 07, 2020 at 02:21:14PM +0000, Derrick Stolee via GitGitGadget wrote: > > This is a second attempt at redesigning Git's repository maintenance > patterns. The first attempt [1] included a way to run jobs in the background > using a long-lived process; that idea was rejected and is not included in > this series. A future series will use the OS to handle scheduling tasks. > > [1] > https://lore.kernel.org/git/pull.597.git.1585946894.gitgitgadget@gmail.com/ > > As mentioned before, git gc already plays the role of maintaining Git > repositories. It has accumulated several smaller pieces in its long history, > including: > > 1. Repacking all reachable objects into one pack-file (and deleting > unreachable objects). > 2. Packing refs. > 3. Expiring reflogs. > 4. Clearing rerere logs. > 5. Updating the commit-graph file. > > While expiring reflogs, clearing rererelogs, and deleting unreachable > objects are suitable under the guise of "garbage collection", packing refs > and updating the commit-graph file are not as obviously fitting. Further, > these operations are "all or nothing" in that they rewrite almost all > repository data, which does not perform well at extremely large scales. > These operations can also be disruptive to foreground Git commands when git > gc --auto triggers during routine use. > > This series does not intend to change what git gc does, but instead create > new choices for automatic maintenance activities, of which git gc remains > the only one enabled by default. > > The new maintenance tasks are: > > * 'commit-graph' : write and verify a single layer of an incremental > commit-graph. > * 'loose-objects' : prune packed loose objects, then create a new pack from > a batch of loose objects. > * 'pack-files' : expire redundant packs from the multi-pack-index, then > repack using the multi-pack-index's incremental repack strategy. > * 'fetch' : fetch from each remote, storing the refs in 'refs/hidden//'. > > These tasks are all disabled by default, but can be enabled with config > options or run explicitly using "git maintenance run --task=". There are > additional config options to allow customizing the conditions for which the > tasks run during the '--auto' option. ('fetch' will never run with the > '--auto' option.) > > Because 'gc' is implemented as a maintenance task, the most dramatic change > of this series is to convert the 'git gc --auto' calls into 'git maintenance > run --auto' calls at the end of some Git commands. By default, the only > change is that 'git gc --auto' will be run below an additional 'git > maintenance' process. > > The 'git maintenance' builtin has a 'run' subcommand so it can be extended > later with subcommands that manage background maintenance, such as 'start', > 'stop', 'pause', or 'schedule'. These are not the subject of this series, as > it is important to focus on the maintenance activities themselves. > > An expert user could set up scheduled background maintenance themselves with > the current series. I have the following crontab data set up to run > maintenance on an hourly basis: > > 0 * * * * git -C / maintenance run --no-quiet >>//.git/maintenance.log One thing I wonder about - now I have to go and make a new crontab (which is easy) or Task Scheduler task (which is a pain) for every repo, right? Is it infeasible to ask for 'git maintenance' to learn something like '--on / --on /'? Or better yet, some config like "maintenance.targetRepo = /"? > > My config includes all tasks except the 'gc' task. The hourly run is > over-aggressive, but is sufficient for testing. I'll replace it with daily > when I feel satisfied. > > Hopefully this direction is seen as a positive one. My goal was to add more > options for expert users, along with the flexibility to create background > maintenance via the OS in a later series. > > OUTLINE > ======= > > Patches 1-4 remove some references to the_repository in builtin/gc.c before > we start depending on code in that builtin. > > Patches 5-7 create the 'git maintenance run' builtin and subcommand as a > simple shim over 'git gc' and replaces calls to 'git gc --auto' from other > commands. For me, I'd prefer to see 'git maintenance run' get bigger and 'git gc --auto' get smaller or disappear. Is there a plan towards that direction, or is that out of scope for 'git maintenance run'? Similar examples I can think of include 'git annotate' and 'git pickaxe'. > > Patches 8-15 create new maintenance tasks. These are the same tasks sent in > the previous RFC. > > Patches 16-21 create more customization through config and perform other > polish items. > > FUTURE WORK > =========== > > * Add 'start', 'stop', and 'schedule' subcommands to initialize the > commands run in the background. > > > * Split the 'gc' builtin into smaller maintenance tasks that are enabled by > default, but might have different '--auto' conditions and more config > options. Like I mentioned above, for me, I'd rather just see the 'gc' builtin go away :) > > > * Replace config like 'gc.writeCommitGraph' and 'fetch.writeCommitGraph' > with use of the 'commit-graph' task. > > > > Thanks, -Stolee > > Derrick Stolee (21): > gc: use the_repository less often > gc: use repository in too_many_loose_objects() > gc: use repo config > gc: drop the_repository in log location > maintenance: create basic maintenance runner > maintenance: add --quiet option > maintenance: replace run_auto_gc() > maintenance: initialize task array and hashmap > maintenance: add commit-graph task > maintenance: add --task option > maintenance: take a lock on the objects directory > maintenance: add fetch task > maintenance: add loose-objects task > maintenance: add pack-files task > maintenance: auto-size pack-files batch > maintenance: create maintenance..enabled config > maintenance: use pointers to check --auto > maintenance: add auto condition for commit-graph task > maintenance: create auto condition for loose-objects > maintenance: add pack-files auto condition > midx: use start_delayed_progress() > > .gitignore | 1 + > Documentation/config.txt | 2 + > Documentation/config/maintenance.txt | 32 + > Documentation/fetch-options.txt | 5 +- > Documentation/git-clone.txt | 7 +- > Documentation/git-maintenance.txt | 124 ++++ > builtin.h | 1 + > builtin/am.c | 2 +- > builtin/commit.c | 2 +- > builtin/fetch.c | 6 +- > builtin/gc.c | 881 +++++++++++++++++++++++++-- > builtin/merge.c | 2 +- > builtin/rebase.c | 4 +- > commit-graph.c | 8 +- > commit-graph.h | 1 + > config.c | 24 +- > config.h | 2 + > git.c | 1 + > midx.c | 12 +- > midx.h | 1 + > object.h | 1 + > run-command.c | 7 +- > run-command.h | 2 +- > t/t5319-multi-pack-index.sh | 14 +- > t/t5510-fetch.sh | 2 +- > t/t5514-fetch-multiple.sh | 2 +- > t/t7900-maintenance.sh | 211 +++++++ > 27 files changed, 1265 insertions(+), 92 deletions(-) > create mode 100644 Documentation/config/maintenance.txt > create mode 100644 Documentation/git-maintenance.txt > create mode 100755 t/t7900-maintenance.sh > > > base-commit: 4a0fcf9f760c9774be77f51e1e88a7499b53d2e2 > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-671%2Fderrickstolee%2Fmaintenance%2Fgc-v1 > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-671/derrickstolee/maintenance/gc-v1 > Pull-Request: https://github.com/gitgitgadget/git/pull/671 > -- > gitgitgadget