RFR: JDK-8175312: SA: clhsdb: Provide an improved heap summary for 'universe' for G1GC

[Stefan Johansson]

Hi Jini,

On 2018-02-27 08:37, Jini George wrote:
> Gentle reminder!
>
> Thanks,
> Jini.
>
> On 2/14/2018 2:37 PM, Jini George wrote:
>> Hello,
>>
>> (Including the SVC and GC groups)
>>
>> Requesting reviews for enabling the clhsdb 'universe' command to 
>> print out the various G1 regions (along with the type).
>>
>> JIRA ID:https://bugs.openjdk.java.net/browse/JDK-8175312
>> Webrev: http://cr.openjdk.java.net/~jgeorge/8175312/webrev.00/index.html
>>
It looks like a file is missing, did you forget to add it to the changeset?
---
open/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/g1/G1CollectedHeap.java:36: 
error: cannot find symbol
import sun.jvm.hotspot.gc.shared.PrintRegionClosure;
---

Otherwise the change looks good, but I would like to see the output 
live. For a big heap this will print a lot of data, just wondering if 
the universe command is the correct choice for this kind of output. I 
like having the possibility to print all regions, so I want the change 
but maybe it should be a different command and 'universe' just prints a 
little more than before. Something like our logging heap-summary at 
shutdown:
garbage-first heap   total 16384K, used 3072K [0x00000000ff000000, 
0x0000000100000000)
  region size 1024K, 4 young (4096K), 0 survivors (0K)
Metaspace       used 6731K, capacity 6825K, committed 7040K, reserved 
1056768K
  class space    used 559K, capacity 594K, committed 640K, reserved 1048576K

Thanks,
Stefan
>> Modifications have been made to display the regions like:
>>
>> ...
>> Region: 0x00000005c5400000,0x00000005c5600000,0x00000005c5600000:Old
>> Region: 0x00000005c5600000,0x00000005c5800000,0x00000005c5800000:Old
>> Region: 0x00000005c5800000,0x00000005c5a00000,0x00000005c5a00000:Old
>> Region: 0x00000005c5a00000,0x00000005c5c00000,0x00000005c5c00000:Old
>> Region: 0x00000005c5c00000,0x00000005c5c00000,0x00000005c5e00000:Free
>> Region: 0x00000005c5e00000,0x00000005c5e00000,0x00000005c6000000:Free
>> Region: 0x00000005c6000000,0x00000005c6200000,0x00000005c6200000:Old
>> ...
>>
>> The jtreg test at this point does not include any testing for the 
>> display of archived or pinned regions. The testing for this will be 
>> added once JDK-8174994 is resolved.
>>
>> The SA tests pass with jprt and Mach5.
>>
>> Thanks,
>> Jini.