Request for review: 8000968: NPG UseCompressedKlassPointers asserts withObjectAlignmentInBytes for > 32G Compressed Oops

[Vladimir Kozlov]

Harold,

New condition is not accurate since it does not take into account 
HeapBaseMinAddress. You need additional condition:

+     } else if (UseCompressedKlassPointers && (mode != 
HeapBasedNarrowOop) &&
+         (Universe::class_metaspace_size() + HeapBaseMinAddress <= 
KlassEncodingMetaspaceMax) &&
+         (KlassEncodingMetaspaceMax + heap_size - 
Universe::class_metaspace_size() <= OopEncodingHeapMax)) {

Vladimir

On 1/22/13 10:22 AM, harold seigel wrote:
> HI Roland,
>
> Thanks again for your comments.  I incorporated them in this new webrev:
> http://cr.openjdk.java.net/~hseigel/bug_8000968_4/
> <http://cr.openjdk.java.net/%7Ehseigel/bug_8000968_4/>
>
> The only changes from the previous webrev are to module universe.cpp.
>
> Could you take another look when you have a chance?
>
> Thanks, Harold
>
> On 1/18/2013 6:44 AM, Roland Westrelin wrote:
>> Hi Harold,
>>
>>> I updated the webrev at
>>> http://cr.openjdk.java.net/~hseigel/bug_8000968_3/<http://cr.openjdk.java.net/%7Ehseigel/bug_8000968_3/>
>>> with this change.
>>   696     } else if ((total_size<= OopEncodingHeapMax)&&  (mode !=
>> HeapBasedNarrowOop)&&
>>   697         (!UseCompressedKlassPointers ||
>>   698           (((OopEncodingHeapMax - heap_size) +
>> Universe::class_metaspace_size())<= KlassEncodingMetaspaceMax))) {
>>
>> heap_size<  OopEncodingHeapMax - KlassEncodingMetaspaceMax is
>> possible, right? Then compressed klass pointers are off with this
>> code. So wouldn't you also want to check for:
>>
>> KlassEncodingMetaspaceMax + heap_size -
>> Universe::class_metaspace_size()<= OopEncodingHeapMax
>>
>> ?
>>
>> and then use KlassEncodingMetaspaceMax -
>> Universe::class_metaspace_size() as base.
>>
>> Roland.