IDEA 15 EAP consumes > 600% CPU on OSX

OSX: Yosemite 10.10.3
IDEA: IU-142.3371.3

With Grails project, relatively small, IDEA usually consumes a HUGE amount of CPU.
This does not related to any actions inside IDE, just after project is opened.
This is looks like UI-related, since if I click File->Invalidate Caches/Restart, and then leave Invalidate dialog opened and rest of Idea UI is blocked, CPU usage goes down from 600% to 4%. Same if I open Settings dialog, or Rename in files dialog, and most probably any modal.

CPU profile is attached

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*Imported from [IDEA-143171](https://youtrack.jetbrains.com/issue/IDEA-143171) · Type: Bug · Votes: 2*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

No source file or test is identified. Start by reproducing the issue with a small Grails project on OSX Yosemite in IDEA IU-142.3371.3, then inspect the attached CPU profile and compare usage with a modal dialog open; done means identifying and fixing the cause of the sustained high CPU usage.

Written by the indexing model from the issue text.