From: Derrick Stolee <stolee@gmail.com>
To: Patrick Steinhardt <ps@pks.im>, git@vger.kernel.org
Cc: Taylor Blau <me@ttaylorr.com>
Subject: Re: [PATCH 3/8] t34xx: don't expire reflogs where it matters
Date: Sun, 22 Feb 2026 19:48:20 -0500 [thread overview]
Message-ID: <86490d73-dee3-4750-b99c-ff94848bcdbb@gmail.com> (raw)
In-Reply-To: <20260220-b4-pks-maintenance-default-geometric-strategy-v1-3-faeb321ad13b@pks.im>
On 2/20/26 5:15 AM, Patrick Steinhardt wrote:
> We have a couple of tests in the t34xx range that rely on reflogs. This
> never really used to be a problem, but in a subsequent commit we will
> change the default maintenance strategy from "gc" to "geometric", and
> this will cause us to drop all reflogs in these tests.
>
> This may seem surprising and like a bug at first, but it's actually not.
> The main difference between these two strategies is that the "gc"
> strategy will skip all maintenance in case the object database is in a
> well-optimized state. The "geometric" strategy has separate subtasks
> though, and the conditions for each of these tasks is evaluated on a
> case by case basis. This means that even if the object database is in
> good shape, we may still decide to expire reflogs.
>
> So why is that a problem? The issue is that Git's test suite hardcodes
> the committer and author dates to a date in 2005. Interestingly though,
> these hardcoded dates not only impact the commits, but also the reflog
> entries. The consequence is that all newly written reflog entries are
> immediately considered stale as our reflog expiration threshold is in
> the range of weeks, only. It follows that executing `git reflog expire`
> will thus immediately purge all reflog entries.
I found these two paragraphs very valuable in explaining this patch.
Thanks!
-Stolee
next prev parent reply other threads:[~2026-02-23 0:48 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-20 10:15 [PATCH 0/8] builtin/maintenance: use "geometric" strategy by default Patrick Steinhardt
2026-02-20 10:15 ` [PATCH 1/8] t: fix races caused by background maintenance Patrick Steinhardt
2026-02-23 16:01 ` Justin Tobler
2026-02-20 10:15 ` [PATCH 2/8] t: disable maintenance where we verify object database structure Patrick Steinhardt
2026-02-23 16:07 ` Justin Tobler
2026-02-20 10:15 ` [PATCH 3/8] t34xx: don't expire reflogs where it matters Patrick Steinhardt
2026-02-23 0:48 ` Derrick Stolee [this message]
2026-02-23 16:15 ` Justin Tobler
2026-02-20 10:15 ` [PATCH 4/8] t5400: explicitly use "gc" strategy Patrick Steinhardt
2026-02-20 10:15 ` [PATCH 5/8] t5510: " Patrick Steinhardt
2026-02-20 10:15 ` [PATCH 6/8] t6500: " Patrick Steinhardt
2026-02-20 10:15 ` [PATCH 7/8] t7900: prepare for switch of the default strategy Patrick Steinhardt
2026-02-20 10:15 ` [PATCH 8/8] builtin/maintenance: use "geometric" strategy by default Patrick Steinhardt
2026-02-23 0:52 ` Derrick Stolee
2026-02-23 9:49 ` Patrick Steinhardt
2026-02-23 16:48 ` Justin Tobler
2026-02-24 8:15 ` Patrick Steinhardt
2026-02-23 0:53 ` [PATCH 0/8] " Derrick Stolee
2026-02-24 8:45 ` [PATCH v2 " Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 1/8] t: fix races caused by background maintenance Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 2/8] t: disable maintenance where we verify object database structure Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 3/8] t34xx: don't expire reflogs where it matters Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 4/8] t5400: explicitly use "gc" strategy Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 5/8] t5510: " Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 6/8] t6500: " Patrick Steinhardt
2026-02-25 10:13 ` Toon Claes
2026-02-24 8:45 ` [PATCH v2 7/8] t7900: prepare for switch of the default strategy Patrick Steinhardt
2026-02-24 8:45 ` [PATCH v2 8/8] builtin/maintenance: use "geometric" strategy by default Patrick Steinhardt
2026-02-24 12:12 ` Derrick Stolee
2026-02-25 10:33 ` Toon Claes
2026-02-24 18:54 ` [PATCH v2 0/8] " Justin Tobler
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