RFR (S): 8129573: CollectedHeap::fill_with_objects() needs to use multiple arrays in 32 bit mode too

[Thomas Schatzl]

Hi all,

  can I have reviews for this small bugfix that got exposed with latest
changes in JDK-8042668?

With that change, we cannot assume that only one object is required to
fill a given memory range, as filler_array_max_size is actually 512k
with G1 now on 32 bit systems (i.e. typically you get 1M regions).

The change just removes the #ifdef __LP64 and fixes the comment.

The problem itself actually only got exposed with the upcoming change
JDK-8129558, where GCBasher acts as a good reproducable test case.

CR:
https://bugs.openjdk.java.net/browse/JDK-8129573

Webrev:
http://cr.openjdk.java.net/~tschatzl/8129573/webrev

Testing:
JPRT (running gcbasher + containing JDK-8129558)

Thanks,
  Thomas