RFR (S) JDK-8014912 Restore PrintSharedSpaces after NPG

[Karen Kinnear]

Ioi,

This will be really helpful - in fact we'd like to use it right now :-)
Would it be hard to track the read-only and read-write separately, so we could at a glance
1) see what metadata is ro vs. rw and
2) see subtotal sizes and percentages (of combined ro/rw) for ro/rw?

thanks,
Karen
On May 22, 2013, at 9:47 PM, Coleen Phillimore wrote:

> 
> Ioi,
> 
> This looks really good.  The only thing is that we have code to create histograms in the VM (see utilities/histogram.hpp). Couldn't you reuse this class instead of writing your own histogram creating function?   It would sort your data for you!  I don't know if it would have the data you are looking for but lots of other jvm code uses this class for a similar purpose.
> 
> Thanks,
> Coleen
> 
> On 5/21/2013 6:29 PM, Ioi Lam wrote:
>> Please review:
>> 
>> http://cr.openjdk.java.net/~iklam/8014912/print_sharedspc_001/
>> 
>> Bug: Restore PrintSharedSpaces functionality after NPG
>> 
>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8014912
>>    https://jbs.oracle.com/bugs/browse/JDK-8014912
>> 
>> Summary of fix:
>> 
>> I added a new enum, MetaspaceObj::Type, which is passed to
>> 
>>    Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
>>                        bool read_only, MetaspaceObj::Type type, TRAPS);
>> 
>> During CDS dumping, all allocations are logged in a linked list to
>> be processed later by metaspaceShared.cpp to generate statistics for
>> objects in the CDS archive. See sample output below.
>> 
>> * No such logging is doneat normal VM execution time so there
>>  is no performance impact.
>> 
>> * I verified that the patch can be applied cleanly on Jon's
>>  recentpatch for JDK-8014862 "Add fast Metasapce capacity and
>>  used per MetadataType"
>> 
>> http://hg.openjdk.java.net/hsx/hotspot-gc/hotspot/rev/2b1a9d972fc2
>> 
>> Testing:
>> 
>>    JPRT, UTE (vm.quick.testlist)
>> 
>> Sample output:
>> 
>>                        ro_cnt   ro_bytes     % | rw_cnt rw_bytes     % |  all_cnt  all_bytes     %
>> --------------------+---------------------------+---------------------------+-------------------------- 
>> Unknown             :        1         64   0.0 | 1         64 0.0 |        2        128   0.0
>> Class               :        0          0   0.0 | 2364    2006080 14.7 |     2364    2006080   9.2
>> Symbol              :    49858    2507168  30.9 | 0          0 0.0 |    49858    2507168  11.5
>> TypeArrayU1         :    13264     608336   7.5 | 2365 428784   3.1 |    15629    1037120   4.8
>> TypeArrayU2         :     4796     341952   4.2 | 0          0 0.0 |     4796     341952   1.6
>> TypeArrayU4         :     2371     178528   2.2 | 0          0 0.0 |     2371     178528   0.8
>> TypeArrayU8         :     3708     365920   4.5 | 0          0 0.0 |     3708     365920   1.7
>> TypeArrayOther      :        0          0   0.0 | 0          0 0.0 |        0          0   0.0
>> Method              :        0          0   0.0 | 32552 3659888  26.8 |    32552    3659888  16.8
>> ConstMethod         :    32552    4099008  50.6 | 0          0 0.0 |    32552    4099008  18.8
>> MethodData          :        0          0   0.0 | 0          0 0.0 |        0          0   0.0
>> ConstantPool        :        0          0   0.0 | 2365    3225600 23.6 |     2365    3225600  14.8
>> ConstantPoolCache   :        0          0   0.0 | 2350    2212320 16.2 |     2350    2212320  10.2
>> Annotation          :       26       1248   0.0 | 0          0 0.0 |       26       1248   0.0
>> MethodCounters      :        0          0   0.0 | 0          0 0.0 |        0          0   0.0
>> SymbolHashentry     :        0          0   0.0 | 49858 1595456  11.7 |    49858    1595456   7.3
>> SymbolBuckets       :        0          0   0.0 | 20011 320176   2.3 |    20011     320176   1.5
>> Other               :        0          0   0.0 | 0     203893 1.5 |        0     203893   0.9
>> --------------------+---------------------------+---------------------------+-------------------------- 
>> Total               :   106576    8102224 100.0 | 111866 13652261 100.0 |   218442   21754485 100.0
>> 
>> 
>> Thanks,
>> Ioi
>> 
>> 
>