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

[Stefan Johansson]

Hi Jini,

This looks good. I'm totally fine with skipping metaspace if that isn't 
displayed for the other GCs.

Cheers,
Stefan

On 2018-03-09 10:29, Jini George wrote:
> Here is the revised webrev:
>
> http://cr.openjdk.java.net/~jgeorge/8175312/webrev.02/
>
> I have made modifications to have the 'universe' command display 
> details like:
>
> hsdb> universe
> Heap Parameters:
> garbage-first heap [0x0000000725200000, 0x00000007c0000000] region 
> size 1024K
> G1 Heap:
>    regions  = 2478
>    capacity = 2598371328 (2478.0MB)
>    used     = 5242880 (5.0MB)
>    free     = 2593128448 (2473.0MB)
>    0.20177562550443906% used
> G1 Young Generation:
> Eden Space:
>    regions  = 5
>    capacity = 8388608 (8.0MB)
>    used     = 5242880 (5.0MB)
>    free     = 3145728 (3.0MB)
>    62.5% used
> Survivor Space:
>    regions  = 0
>    capacity = 0 (0.0MB)
>    used     = 0 (0.0MB)
>    free     = 0 (0.0MB)
>    0.0% used
> G1 Old Generation:
>    regions  = 0
>    capacity = 155189248 (148.0MB)
>    used     = 0 (0.0MB)
>    free     = 155189248 (148.0MB)
>    0.0% used
>
>
> I did not add the metaspace details since that did not seem to be in 
> line with the 'universe' output for other GCs. I have added a new 
> command "g1regiondetails" to display the region details, and have 
> modified the tests accordingly.
>
> hsdb> g1regiondetails
> Region Details:
> Region: 0x0000000725200000,0x0000000725200000,0x0000000725300000:Free
> Region: 0x0000000725300000,0x0000000725300000,0x0000000725400000:Free
> Region: 0x0000000725400000,0x0000000725400000,0x0000000725500000:Free
> Region: 0x0000000725500000,0x0000000725500000,0x0000000725600000:Free
> Region: 0x0000000725600000,0x0000000725600000,0x0000000725700000:Free
> Region: 0x0000000725700000,0x0000000725700000,0x0000000725800000:Free
> ...
>
> Thanks,
> Jini.
>
>
> On 2/28/2018 12:56 PM, Jini George wrote:
>> Thank you very much, Stefan. My answers inline.
>>
>> On 2/27/2018 3:30 PM, Stefan Johansson wrote:
>>> Hi Jini,
>>
>>>>> 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?
>>
>> Indeed, I had missed that! I added the missing file in the following 
>> webrev:
>>
>> http://cr.openjdk.java.net/~jgeorge/8175312/webrev.01/
>>
>>> ---
>>> 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
>>
>> Ok, will add this, and could probably have the region details 
>> displayed under a new command called "g1regiondetails", or some such, 
>> and send out a new webrev.
>>
>> Thanks,
>> Jini.
>>
>>>
>>> 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.
>>>