performance degradation in Array::newInstance on -XX:TieredStopAtLevel=1

Martin Buchholz martinrb at
Fri Jan 4 18:31:03 UTC 2019

On Thu, Jan 3, 2019 at 11:26 PM Сергей Цыпанов <sergei.tsypanov at>

> I've run into this performance effect while investigating creation of
> Spring's ConcurrentReferenceHashMap,
> it turned out that it used Array::newInstance to create array of
> References stored in a map's Segment:

Slight tangent - ConcurrentHashMap used to use Segments, but no longer
does.  Probably  ConcurrentReferenceHashMap is based on an old version of
ConcurrentHashMap and would benefit from a re-port.

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