Speed up git changelog generation

Generation of change log takes significant time in case there are many commits between builds.

Per build logs, hudson issues

[workspace] $ git log --pretty=format:%H 961016ffca61b0cf4ef8cc33816b8c3496ac73b2..1074f07c642d6f9f5259c2092751a424ed6c4667

and then for every commit

[workspace] $ git log -M --summary --pretty=raw -n 1 1074f07c642d6f9f5259c2092751a424ed6c4667
[workspace] $ git diff-tree -M -r 1074f07c642d6f9f5259c2092751a424ed6c4667

In my case special job that was building minor changes that were rebased onto long history of non-related commit took 2 minutes to build, and 1h 40 minutes to compute change log for 900 commits.

Can it be improved by e.g. introducing detail-less changelog, so that single "git log" statement gives hashes/messages/authors, and hudson shows no "deatails" link (gitweb link only is enough)?