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I'm reinstating this request as is.<br>
<br>
The observed failure which caused me to withdraw this is<br>
due to a different bug 8022817. The fix for 8022817 will<br>
be reviewed separately.<br>
<br>
Thanks.<br>
<br>
Jon<br>
<br>
<div class="moz-cite-prefix">On 7/30/13 3:52 PM, Jon Masamitsu
wrote:<br>
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<blockquote cite="mid:51F843A5.3010906@oracle.com" type="cite">
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The partitioning of eden for parallel CMS initial mark and remark
<br>
depends of the setting of _eden_chunk_index to correctly reflect<br>
the occupancy of eden. For example if _eden_chunk_index is 3,<br>
then eden should be dividable into 3 chunks, each chunk<br>
available for parallel processing. In particular after a young<br>
gen collection when eden is empty, the broken code depends on<br>
_eden_chunk_index being 0. The resetting of _eden_chunk_index<br>
is done in the gc_epilogue() of the CMS gen. When<br>
<br>
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1) a System.gc() is called <br>
<br>
and <br>
<br>
2) UseCMSCompactAtFullCollection is set to false <br>
<br>
the CMS generation tells GenCollectedHeap that CMS <br>
does not collect the young gen. So the young gen is<br>
collected first and then the CMS gen is collected. In<br>
this case the CMS gen gc_epilogue() is not called<br>
after the young gen collection and _eden_chunk_index<br>
is not cleared. The gc_epilogue() methods are called after the<br>
completion of the collection (after the CMS gen is<br>
collected). This is the expected behavior for when the<br>
gc_epilogue() is called.<br>
<br>
This fix adds a guard that checks if eden is empty, <br>
skipping eden processing if it is.<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://cr.openjdk.java.net/%7Ejmasa/8021809/webrev.00/">http://cr.openjdk.java.net/~jmasa/8021809/webrev.00/</a>
</blockquote>
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