large/active wikis are getting slow to display

Summary

Wiki instances that have been actively used and contain a lot of objects, are getting slow over time.

Steps to reproduce

Use wiki a loat, create many pages/revisions or upload lots of files.

What is the current bug behavior?

Wiki pages take a long time to load.

What is the expected correct behavior?

Fast loading of wiki pages, like it is for new or small wikis.

Possible fixes

Running a "git gc" on the git repository that contains the wiki fixes the issue. This should be run periodically, or at least from time to time. Maybe this can be integrated into the regular "housekeeping tasks" that are run on other git repositories.