Large increase in startup time from JDK8 to JDK9

[Andrew Haley]

I've been noticing a significant increase in startup time, and decided
to investigate.

With JDK8 -XX:+TraceBytecodes on HelloWorld I see:

760620 bytecodes executed in 13.5s (0.056MHz)
[BytecodeCounter::counter_value = 760620]

And with JDK9 I see:

4916036 bytecodes executed in 120.0s (0.041MHz)
[BytecodeCounter::counter_value = 4916036]

I'm guessing this is because of Jigsaw processing, but I haven't
investigated any further.  I would have thought that such a severe
degradation was a release blocker.

Does anyone here know about this?  Has anyone investigated?

Andrew.