Repository import is slow

I just tried running sudo gitlab-rake gitlab:elastic:index_repositories, and it is taking a long time to index my repositories. I ran tcpdump to snoop on the Elasticsearch port 9200, and I noticed each individual commit is being inserted one at a time:

https://gitlab.com/gitlab-org/gitlab-elasticsearch-git/blob/master/lib/elasticsearch/git/repository.rb#L184

One thing that may help is to use the bulk API to insert multiple records at once.