request for review (s) - 8005452: Create new flags for Metaspace resizing policy

[Jon Masamitsu]

I've update the webrev2 (now 2 separate webrevs)  for review comments.

8005452: NPG: Create new flags for Metaspace resizing policy

http://cr.openjdk.java.net/~jmasa/8005452/webrev.03/

8006815: NPG: Trigger a GC for metadata collection just before the 
threshold is exceeded.

http://cr.openjdk.java.net/~jmasa/8006815/webrev.01/


On 1/16/2013 8:50 AM, Jon Masamitsu wrote:
> I've added checks to arguments.cpp that are analogous to the
> checks for MinHeapFreeRatio / MaxHeapFreeRatio
>
> Changes since webrev.00 are in arguments.cpp
>
> http://cr.openjdk.java.net/~jmasa/8005452/webrev.01/
>
> Thanks, Vitaly.
>
> Jon
>
> On 1/15/2013 5:55 AM, Vitaly Davidovich wrote:
>> Hi Jon,
>>
>> Does it make sense to validate that the new flags are consistent 
>> (I.e. max
>>> = min)? That is, if user changes one or both such that max<  min, 
>>> should
>> VM report an error and not start?
>>
>> Thanks
>>
>> Sent from my phone
>> On Jan 14, 2013 10:31 AM, "Jon Masamitsu"<jon.masamitsu at oracle.com>  
>> wrote:
>>
>>> 8005452: Create new flags for Metaspace resizing policy
>>>
>>> Previously the calculation of the metadata capacity at which
>>> to do a GC (high water mark, HWM) to recover
>>> unloaded classes used the MinHeapFreeRatio
>>> and MaxHeapFreeRatio to decide on the next HWM.  That
>>> generally left an excessive amount of unused capacity for
>>> metadata.  This change adds specific flags for metadata
>>> capacity with defaults more conservative in terms of
>>> unused capacity.
>>>
>>> Added an additional check for doing a GC before expanding
>>> the metadata capacity.  Required adding a new parameter to
>>> get_new_chunk().
>>>
>>> Added some additional diagnostic prints.
>>>
>>> http://cr.openjdk.java.net/~**jmasa/8005452/webrev.00/<http://cr.openjdk.java.net/~jmasa/8005452/webrev.00/> 
>>>
>>>
>>> Thanks.
>>>