SourceTree high CPU usage

After upgrading to SourceTree Version 2.7 (152) today I'm seeing high CPU usage when SourceTree is running with one of my repositories open. I see sustained CPU usage from 90-100% (of one core) for around 30 seconds, which then reduces to 30-40%. It seems to spike back up to near 100% when the SourceTree window is in the background without focus (e.g. it's doing that as I write this report while SourceTree is behind my web browser).

High CPU usage continues even after I close the repository window, until I quit and restart SourceTree. I have seen it drop back down to ~1-2% as well but when I first noticed the issue, SourceTree was hovering at high CPU usage even after I hadn't interacted with it for a while.

I am seeing this with multiple private Git repositories from my company's Bitbucket account, but not with every repository. Unfortunately I haven't found an open source repository that I can reproduce this problem with yet. I realize this would be a much better bug report with a repro against a publicly available repository – I don't have time to do more searching for one today but let me know if that is critical and I will try to get a better repro when I can.

I did not see this problem prior to upgrading to 2.7 today.