RFR (M): 8014659: NPG: performance counters for compressed klass space

[Erik Helin]

On 2013-08-16, harold seigel wrote:
> Hi Erik,
> 
> Thanks for doing the work of merging our two changes.  I had one
> small comment.  In MetaspaceAux::reserved_in_bytes() could you
> change this
> 
>    size_t reserved = list == NULL ? 0 : list->virtual_space_total();
>    return reserved;
> 
> to
> 
>    return list == NULL ? 0 : list->virtual_space_total();

Nice catch, thanks! I've uploaded a new webrev to:
http://cr.openjdk.java.net/~ehelin/8014659/webrev.05/

The incremental changes since the first webrev are list below:
- http://cr.openjdk.java.net/~ehelin/8014659/webrev.04-05/
- http://cr.openjdk.java.net/~ehelin/8014659/webrev.03-04/
- http://cr.openjdk.java.net/~ehelin/8014659/webrev.02-03/
- http://cr.openjdk.java.net/~ehelin/8014659/webrev.01-02/
- http://cr.openjdk.java.net/~ehelin/8014659/webrev.00-01/

Thanks,
Erik

> Thanks, Harold
> 
> 
> On 8/16/2013 6:22 AM, Erik Helin wrote:
> >On 2013-08-15, Mikael Gerdin wrote:
> >>Erik,
> >>
> >>On 08/14/2013 04:49 PM, Erik Helin wrote:
> >>>Hi all,
> >>>
> >>>this change adds performance counters for compressed class space.
> >>>
> >>>Webrev:
> >>>http://cr.openjdk.java.net/~ehelin/8014659/webrev.00/
> >>>
> >>>Changes to hotspot:
> >>>The main changes are in metaspaceCounters.hpp and metaspaceCounters.cpp,
> >>>where the class MetaspaceCounters has been split up into
> >>>MetaspaceCounters and MetaspacePerfCounters. MetaspaceCounters now owns
> >>>an instance of MetaspacePerfCounters. The class
> >>>CompressedClassSpaceCounters has been added which also has its own
> >>>instance of MetaspacePerfCounters. MetaspacePerfCounters initializes and
> >>>updates the actual performance counters.
> >>I'm a bit concerned about the exception handling in the perf
> >>variable creation. But it appears to be similar to the other places
> >>where perf variables are created.
> >>
> >>Creating a 0-reporting perf counter if -UseCompressedKlassPointers
> >>seems consistent with the rest of the code.
> >>
> >>I'd say this is fine, but as Coleen mentioned you should verify this
> >>with Harold's change for CDS+CompressedOops.
> >Coleen, Mikael,
> >
> >I've rebased the change on top of hotspot-rt (which includes Harold's
> >change). I had to resolve some merge conflicts in metaspace.cpp.
> >
> >Please see the latest (and hopefully final) webrev at:
> >http://cr.openjdk.java.net/~ehelin/8014659/webrev.04/
> >
> >The incremental changes since the first webrev are listed below:
> >- http://cr.openjdk.java.net/~ehelin/8014659/webrev.03-04/
> >- http://cr.openjdk.java.net/~ehelin/8014659/webrev.02-03/
> >- http://cr.openjdk.java.net/~ehelin/8014659/webrev.01-02/
> >- http://cr.openjdk.java.net/~ehelin/8014659/webrev.00-01/
> >
> >I plan to push this to hotspot-rt as well, since the change now depends
> >on Harold's change.
> >
> >Thanks,
> >Erik
> >
> >>>The changes in metaspace.hpp/cpp were needed to get some additional data
> >>>from the metaspace data structures. The method
> >>>free_chunks_in_total(mdtype) was made public and the method
> >>>free_bytes(mdtype) was added. Some common functionality was extracted
> >>>into get_space_list(mdtype) which got rid of some duplicated code.
> >>>
> >>>The changes in:
> >>>- g1MonitorinSupport.cpp
> >>>- parallelScavengeHeap.cpp
> >>>- genCollectedHeap.cpp
> >>>- universe.cpp
> >>>are only "one-liners" that either update or initialize the new performance
> >>>counters.
> >>>
> >>>Changes to the testlibrary:
> >>>- Added Asserts.java for writing asserts like "assertTrue",
> >>>   "assertEquals", etc.
> >>>- Added PerfCounter.java and PerfCounters.java to make it easy to
> >>>   inspect performance counters for the currently running VM.
> >>>- Added InputArguments.java so a test can check the arguments it got
> >>>   passed.
> >>>- Added InMemoryJavaCompiler.java for compiling a string into bytecode.
> >>>   Useful for loading classes generated at runtime without using files.
> >>>- Added ByteCodeLoader.java for defining a new class when you already
> >>>   have the bytecode.
> >>The test code looks fine.
> >>
> >>/Mikael
> >>>Testing:
> >>>- Added the new test TestMetaspacePerfCounters.java
> >>>- JPRT
> >>>
> >>>Bug:
> >>>http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8014659
> >>>
> >>>Thanks,
> >>>Erik
> >>>
>