RFR: 8064814: Print more helpful error message when getting OOM due to low Java Heap base when running with CompressedOops

[Coleen Phillimore]

Poonam,

This looks good, except can you use

+ switch (Universe::narrow_oop_mode()) {
+ case 0: ... + case 1:

These instead:

     UnscaledNarrowOop  = 0,
     ZeroBasedNarrowOop = 1

Thanks,
Coleen

On 5/10/16 4:04 PM, Poonam Bajaj Parhar wrote:
> Hello,
>
> Could I get reviews for this small change, please!
> http://cr.openjdk.java.net/~poonam/8064814/webrev.00/
>
> Thanks,
> Poonam
>
> On 5/5/2016 6:49 AM, poonam.bajaj at oracle.com wrote:
>> Hello,
>>
>> Please review this simple fix for:
>> Bug 8064814 <https://bugs.openjdk.java.net/browse/JDK-8064814> : Print
>> more helpful error message when getting OOM due to low Java Heap base
>> when running with CompressedOops
>> Webrev: http://cr.openjdk.java.net/~poonam/8064814/webrev.00/
>>
>> Problem: We can encounter out-of-native-heap errors when the Java heap
>> is either placed in the first 4gb or 32gb address space when running
>> with the CompressedOops. The Java Heap base in these cases limits and
>> blocks the growth of the native heap.
>>
>> Fix: Print better error message giving an indication that the
>> out-of-native heap error may be due to the use of CompressedOops and how
>> it can be resolved. These changes also check if the process is running
>> in 32-bit mode and then print the appropriate 32-bit or 64-bit related
>> suggestions.
>>
>> Testing: Manual testing
>>
>> Thanks,
>> Poonam
>>
>