git hogs the CPU, RAM and storage despite its config

What did you do before the bug happened? (Steps to reproduce your issue)

many: git add -v --force -- "${file_path}/${file_name}" git commit -v -m "${full_commit_message}" -o -- "${file_path}/${file_name}"

What did you expect to happen? (Expected behavior)

I expected git to respect the configuration (.git/config):
[core]
    repositoryformatversion = 0
    filemode = false
    bare = false
    logallrefupdates = true
    fsmonitor = true
    untrackedcache = true
[remote "origin"]
    url = git@examle.com:ppa
    fetch = +refs/heads/*:refs/remotes/origin/*
[branch]
    autosetuprebase = always
[branch "main"]
    remote = origin
    merge = refs/heads/main
    rebase = true
[feature]
    manyFiles = true
[fetch]
    writeCommitGraph = true
[gc]
    auto = 0
[pack]
    threads = 1
    windowMemory = 1g

I expected git to use maximum one thread for packing and I'm surprised it even tried to perform packing as gc.auto was disabled.

What happened instead? (Actual behavior)

Instead, it used all the threads it could find (28 out of 32), depriving the whole server of CPU, RAM and storage as the tmp files kept piling up.

What's different between what you expected and what actually happened?

Uncontrollable use of CPU threads, RAM and storage

Anything else you want to add:

All the threads were running: git pack-objects --local --delta-base-offset --honor-pack-keep .git/objects/pack/.tmp-<number>-pack

Please review the rest of the bug report below. You can delete any lines you don't wish to share.

[System Info]
git version:
git version 2.51.0
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
libcurl: 8.14.1
zlib: 1.3.1
SHA-1: SHA1_DC
SHA-256: SHA256_BLK
default-ref-format: files
default-hash: sha1
uname: Linux 6.17.0-23-generic #23-Ubuntu SMP PREEMPT_DYNAMIC Sat Apr
11 23:29:57 UTC 2026 x86_64
compiler info: gnuc: 15.2
libc info: glibc: 2.42
$SHELL (typically, interactive shell): /bin/bash

[Enabled Hooks]