Eden space is not empty after a Full GC?

[Y Srinivas Ramakrishna]

[What Jon said. Of course I was ignoring (but should not have)
the case where the live data size exceeds the size of old gen. As
Jon indicated that's usually the most common case. (I was assuming,
but should not have, that you were concerned about situations where
all the free space in old gen was not used, yet there were objects left
behind in Eden following compaction.)]

>>
>> Could you point me to the code where the full GC found it cannot slide
>> this huge chunk?
>

Look at the macro SCAN_AND_FORWARD() in space.hpp
for the serial mark-compact code where the forwarding
addresses are computed in the framework collectors.

Or for similar code in the PS collector, see 
PSMarkSweepDecorator::precompact().

The computation of the forwarding addresses in the case of parallel
compact is sufficiently different that I'll let Jon or John point you
to the relevant code.

-- ramki.


>>
>> Thanks,
>> Neo
>>
>>>
>>> Are there other situations where you see a non-empty Eden
>>> following a mark-compact full collection?
>>>
>>> >
>>> > Is there any implementation concern for this? Can I force the full GC
>>> > to clean the eden space?
>>>
>>>
>>> A full gc would do a mark-compact collection.
>>>
>>> -- ramki.
>>>
>>> >
>>> > Thanks,
>>> > Neo
>>>
>>>
>>> -- 
>>>
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>>> Y. Srinivas Ramakrishna               HotSpot JVM
>>> Sun Microsystems, Inc., USCA 22-123   CSG / Sun Software
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>>
>>

-- 

----------------------------------------------------------------------------
Y. Srinivas Ramakrishna               HotSpot JVM
Sun Microsystems, Inc., USCA 22-123   CSG / Sun Software
4220 Network Circle                   408 276 7250 (x17250)
Santa Clara, CA  95054, U.S.A.        Y dot S dot Ramakrishna at Sun dot COM
----------------------------------------------------------------------------
----------------- Sun Proprietary / Confidential ---------------------------

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NOTICE: This email message is for the sole use of the intended recipient(s)
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