emerge --sync したあと git が動きつづけてるんだけど何これ？

root 30734 0.0 0.0 10848 1400 ? Ss 03:49 0:00 /usr/libexec/git-core/git gc --auto --no-quiet
root 30735 0.0 0.1 10848 1908 ? S 03:49 0:00 /usr/libexec/git-core/git repack -d -l -A --unpack-unreachable=2.weeks.ago --keep-pack=pack-380ccb31b4b0adc372730fee957139ca03bfeac8.pack
root 30736 22.4 47.4 1699028 719572 ? R 03:49 2:58 /usr/libexec/git-core/git pack-objects --local --delta-base-offset .git/objects/pack/.tmp-30735-pack --keep-true-parents --honor-pack-keep --keep-pack=pack-380ccb31b4b0adc372730fee957139ca03bfeac8.pack --non-empty --all --reflog --indexed-objects --unpack-unreachable=2.weeks.ago