RFR: 8013590: NPG: Add a memory pool MXBean for Metaspace

[Jon Masamitsu]

Erik,

http://cr.openjdk.java.net/~ehelin/8013590/webrev.00/src/share/vm/services/memoryPool.hpp.frames.html

For _undefined_size you could use max_uintx defined in 
globalDefinitions.hpp.
Using the name max_uintx makes it a little more clear that undefined mean
a maximum value instead of an error value.

http://cr.openjdk.java.net/~ehelin/8013590/webrev.00/src/share/vm/services/memoryService.hpp.frames.html

Really a nit but instead of

   77   static MemoryPool*                    _cks_pool;


_cks_pool really tells an reader very little.  Would you
consider _compressed_klass_pool?  Or even
_cklass_pool?

http://cr.openjdk.java.net/~ehelin/8013590/webrev.00/test/gc/metaspace/TestMetaspaceMemoryPool.java.html

The functions assertEquals(), assertTrue(), and assertDefined() seem 
useful.  Is there
a more global place where they can be put so other can use them?

Rest looks good.

Jon


On 5/28/13 9:22 AM, Erik Helin wrote:
> Hi all,
>
> this change adds two memory pools for metaspace, one for Metaspace and
> one for compressed klass space. The memory pool for compressed klass
> space will only have valus that differ from 0 or -1 (undefined) if
> compressed klass pointers are used.
>
> This change also adds a manager for the pools: Metaspace Manager.
>
> I have also added a test that checks that the metaspace manager is
> present and that the two pools are present. The test also verifies that
> the compressed klass space pool act correct according to the
> UseCompressedKlass flag.
>
> The last time I added metaspace memory pools, it triggered some
> unforeseen bugs:
> - Two asserts in jmm_GetMemoryUsage that asserted that a memory pool was
>    either of heap type or had an undefined init/max size.
> - The jdk/test/java/lang/management/MemoryMXBean/MemoryTest.java failed
> - The service lock was taken out of order with the metaspace locks
>
> These bugs have all been fixed:
> - The asserts have been removed since they are no longer true
> - The test has been updated but is not part of this change since it is a
>    JDK change
> - This change does not make use of functions requiring the metaspace
>    lock. I had to remove some verification code in free_chunks_total to
>    ensure this.
>
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8013590/webrev.00/
>
> Testing:
> - One new jtreg test
> - JPRT
> - All the tests that failed in nighly testing last time now pass
>
> Thanks,
> Erik

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