From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout-a8-smtp.messagingengine.com (fout-a8-smtp.messagingengine.com [103.168.172.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D89E819CC14 for ; Thu, 12 Feb 2026 06:37:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770878274; cv=none; b=KIqW0g2h/Wi5BIj3iqMyDs1/actYKZtSHggNIOEiVUzZucDNPVb/xKy+o3b6098zm+47nS9cKAvloO+2V1nb8R5rvk5d3Ngwuh2ZRHw6LjtcTbLoLbDyZM9mXMIrXwKTuFEulSUuYye63iPK5YrXw6lMgEkhnxn88ZwGsAN/oBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770878274; c=relaxed/simple; bh=fR1qK0M4WStquVW/bZ36dMKk6r7bW5lW209jM9kj5KQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fkfE2ygr4NO7BEUwQsFv7+PrOnuQpQLEjYDLRfWOQpw8IhtPl2tZlRqWE4AVCwFIdgWkwUOe9nPbeGj/7rNNJJxSk439ZJYLOv2QG5cIkfMZmo7c9solzYUKIhDk/Pf61c1+6h35L9R5mokDY/huPOvzPRGpqX383r22YZYlxgY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pks.im; spf=pass smtp.mailfrom=pks.im; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b=LYYio1xO; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=ODZmG67K; arc=none smtp.client-ip=103.168.172.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pks.im Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pks.im Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b="LYYio1xO"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="ODZmG67K" Received: from phl-compute-02.internal (phl-compute-02.internal [10.202.2.42]) by mailfout.phl.internal (Postfix) with ESMTP id 044F3EC05EB; Thu, 12 Feb 2026 01:37:52 -0500 (EST) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-02.internal (MEProxy); Thu, 12 Feb 2026 01:37:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=cc:cc :content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm3; t=1770878272; x=1770964672; bh=k7FR7C4xKW VR9yQy7v6jdiCbER4mTgYSeMfUJG9jS4E=; b=LYYio1xOjmXvkACWcOdMqRUH3x rtPqXPMGYZi0fAMgqeYWDuGkXjVI5vmrawXheNDvvBTYBttk68VzenzqSYShC0/B MJaHM3Kz0yH1UZuS+X43sGqrx40fY3T69AmgGSxptZNA7POns4RneG+vsDb3q8l+ qHUKEHhQHr0/33yiCYG5zGJav7+7wJw5uuuf9DFgtp+gtlwWVd8QUd9BSmxIFo3+ 9IhDN6plamRgdf5s6eHgc70OlbWiK4/V98dj09pJK7CsFW/0iLKWxuHHbnMRpUDM A8iIfWqgOgKfVEzz87Y069LO1L3hgjgDY3axhSyzZresyIHRiRdD+yskfPOg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t= 1770878272; x=1770964672; bh=k7FR7C4xKWVR9yQy7v6jdiCbER4mTgYSeMf UJG9jS4E=; b=ODZmG67KZxKyaDLPX132iJb09Yc5LletvHow87Tn0aTOrOxh0dX UpCaLaRgVoOFeNuNleP8+8pyJAnGUQlzpKOeLc+XuPnxN8tYXMUC8aTMXWNDDDRT 6tMCw+laCC4yyDpSAHRkDsWUUwnxQHUkxrJ3ndPLtBuXgI8sGiC3DQDJqqFfIHw3 KmIa764P7cfnDRpqNnNAWGW38rNN/691W60wnDDckc5ky4xox4NzJNOD4qdmOsyO VCCNECU7I8FG3RpjPyQzMeBHtfAdt/V7WBlHPMb1HiPyrNUSxdPyOzy0kmpkAavV z+dmxikDmiOWFQhHe8M0zNQFRek3Sb3YHWQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgddvtdegieelucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf gurhepfffhvfevuffkfhggtggujgesthdtredttddtvdenucfhrhhomheprfgrthhrihgt khcuufhtvghinhhhrghrughtuceophhssehpkhhsrdhimheqnecuggftrfgrthhtvghrnh epveekkeffhfeitdeludeigfejtdetvdelvdduhefgueegudfghfeukefhjedvkedtnecu vehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepphhssehpkh hsrdhimhdpnhgspghrtghpthhtohepfedpmhhouggvpehsmhhtphhouhhtpdhrtghpthht ohepghhithhsthgvrhesphhosghogidrtghomhdprhgtphhtthhopehgihhtsehvghgvrh drkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhifrghnkhhosehgihhtlhgrsgdrtgho mh X-ME-Proxy: Feedback-ID: i197146af:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 12 Feb 2026 01:37:51 -0500 (EST) Received: by mail (OpenSMTPD) with ESMTPSA id 50c54090 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 12 Feb 2026 06:37:50 +0000 (UTC) Date: Thu, 12 Feb 2026 07:37:47 +0100 From: Patrick Steinhardt To: Junio C Hamano Cc: git@vger.kernel.org, Lukas Wanko Subject: Re: [PATCH] builtin/pack-objects: don't fetch objects when merging packs Message-ID: References: <20260211-pks-pack-objects-stdin-skip-backfill-fetch-v1-1-870cad56d8ae@pks.im> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Feb 11, 2026 at 09:21:16AM -0800, Junio C Hamano wrote: > Patrick Steinhardt writes: > > > The "--stdin-packs" option can be used to merge objects from multiple > > packfiles given via stdin into a new packfile. One big upside of this > > option is that we don't have to perform a complete rev walk to enumerate > > objects. Instead, we can simply enumerate all objects that are part of > > the specified packfiles, which can be significantly faster in very large > > repositories. > > > > There is one downside though: when we don't perform a rev walk we also > > don't have a good way to learn about the respective object's names. As a > > consequence, we cannot use the name hashes as a heuristic to get better > > delta selection. > > > > We try to offset this downside though by performing a localized rev > > walk: we queue all objects that we're about to repack as interesting, > > and all objects from excluded packfiles as uninteresting. We then > > perform a best-effort rev walk that allows us to fill in object names. > > > > There is one gotcha here though: when "--exclude-promisor-objects" has > > not been given we will perform backfill fetches for any promised objects > > that are missing. This used to not be an issue though as this option was > > mutually exclusive with "--stdin-packs". But that has changed recently, > > and starting with dcc9c7ef47 (builtin/repack: handle promisor packs with > > geometric repacking, 2026-01-05) we will now repack promisor packs > > during geometric compaction. The consequence is that a geometric repack > > may now perform a bunch of backfill fetches. > > > > We of course cannot passe "--exclude-promisor-objects" to fix this > > issue -- after all, the whole intent is to repack objects part of a > > promisor pack. But arguably we don't have to: the rev walk is intended > > as best effort, and we already configure it to ignore missing links to > > other objects. So we can adapt the walk to unconditionally disable > > fetching any missing objects. > > "passe" -> "pass". Oops, right. Fixed locally, and I saw that you also fixed it in your version. > Other than that, very nicely described, and the implementation is > surprisingly simple (thanks to a single global variable, and > asumption that makes it safe to use such a single global variable, > i.e., there is just one packing operation running at a time). > > Will queue. Thanks. Thanks! Patrick