I finally found the culprit. It is the process called SafariBookmarksSyncAgent which respawns after force quit and seems to appear even if you do not have Safari syncing to iCloud enabled.
Workaround: boot your computer before opening PT session and keep your Activity Monitor open. When it starts to eat memory, force quit it and it stays calm for a while.
Today my tests showed that in 10 hours that process had read 10 gigabytes of bookmarks and written 20 gigabytes of the same stuff. Go figure. Bookmarks file is kilobytes. So it is doing read/write all the time.
This is a workaround and not a final solution, mind you. I am trying to find out what else gets broken if that thing is permanently disabled from UNIX side of things.
Darryl, are you interested already?
