-Xcomp test time regressions?

[Aleksey Shipilev]

Hi,

I was doing the usual work, and then noticed -Xcomp tests got considerably slower. I believe there 
are plenty of JBS bug reports already with various test timeouts.

Running a sample test like:
   $ CONF=linux-x86_64-server-fastdebug make run-test 
TEST=gc/shenandoah/mxbeans/TestPauseNotifications.java TEST_VM_OPTS="-Xcomp"

I initially thought it has something to do with JTReg upgrade, but it does not look like it:
   - 18, JTReg 6+1: 5m33s (!!!)
   - 11u, JTReg 5.1-b01: 2m27s
   - 11u, JTReg 6+1: 2m32s

Comparing the test logs between "slow" 18 and fast "11u", I can see that javac tasks take a lot more 
(whole minutes more!) time in "slow" configs.

Before I go and bisect this more thoroughly, is this an already known thing?

-- 
Thanks,
-Aleksey