Review request (S) JDK-8004241 NPG: Metaspace occupies more memory than specified by -XX:MaxMetaspaceSize option

Jon Masamitsu jon.masamitsu at oracle.com
Wed Mar 20 17:14:54 PDT 2013


We switched the hotspot release to hsx25 (from hsx24) when NPG was 
integrated so
hs25.b02.  There was some problem with b01 that I think was unrelated to
NPG.

Jon

On 3/20/2013 12:49 PM, Srinivas Ramakrishna wrote:
> One somewhat weakly related question (pardon the abuse of this thread,
> but I figured it might be easy to get a quick response since we are on
> the topic of NPG :-) : In what release of HS (HSXX.X-BXX) did NPG get
> enabled?
>
> thanks!
> -- ramki
>
> On Wed, Mar 20, 2013 at 9:30 AM, John Cuthbertson
> <john.cuthbertson at oracle.com> wrote:
>> Hi Mikael,
>>
>> Your change looks good to me.
>>
>> Cheers,
>>
>> JohnC
>>
>>
>> On 3/7/2013 12:54 AM, Mikael Gerdin wrote:
>>> Hi
>>>
>>>
>>> When deciding when to reserve more metaspace memory we erroneously looked
>>> only at the "capacity" of the metaspace insted of the reserved space (which
>>> is what we ask this function when expanding).
>>>
>>> Additionally, we didn't check MaxMetaspaceSize against the sum of
>>> reserved(Class) + reserved(NonClass) which caused us to use more than
>>> MaxMetaspaceSize even when it was set.
>>>
>>> Bug:
>>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8004241
>>> (not yet available at the time of writing this mail)
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~mgerdin/8004241/webrev.0
>>>
>>> Testing:
>>> JPRT with -XX:MaxMetaspaceSize set for all tests to exercise the code
>>> path.
>>



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