Example commit: https://gitlab.com/gitlab-org/gitlab-ce/commit/452c076a34cc11cc97f4b1c3113e86ce4367e05  It appears: * 58% of the time is spent on highlighting individual lines * 29% of the time is spent rendering HAML From  [commit-prof.zip](/uploads/b41c91318e6c81fafdd0547f74f56e2b/commit-prof.zip)