G1gc compaction algorithm

[Martin Makundi]

Strange that it is in the property summary but doesn't allow setting it.


2014-08-01 0:39 GMT+03:00 Martin Makundi <martin.makundi at koodaripalvelut.com
>:

> Hi!
>
> UnlockDiagnosticVMOptions  is on (though later (on the right side) in the
> command line). Jvm version is
>
> java version "1.7.0_55"
> Java(TM) SE Runtime Environment (build 1.7.0_55-b13)
> Java HotSpot(TM) 64-Bit Server VM (build 24.55-b03, mixed mode)
>
>
>
> 2014-08-01 0:37 GMT+03:00 Yu Zhang <yu.zhang at oracle.com>:
>
>  Martin,
>>
>> These 2 need to run with  -XX:+UnlockDiagnosticVMOptions
>>
>> Thanks,
>> Jenny
>>
>> On 7/31/2014 2:33 PM, Martin Makundi wrote:
>>
>> Hi!
>>
>>  G1SummarizeRSetStats does not seem to work, jvm says:
>>
>>  Improperly specified VM option 'G1SummarizeRSetStatsPeriod=10'
>> Error: Could not create the Java Virtual Machine.
>> Error: A fatal exception has occurred. Program will exit.
>>
>>  Same for both new options
>>
>>
>>
>> 2014-07-31 20:22 GMT+03:00 Yu Zhang <yu.zhang at oracle.com>:
>>
>>> Martin,
>>>
>>> The ScanRS for mixed gc is extremely long, 1000-9000ms.  Because it is
>>> over pause time goal, minimum old regions can be added to CSet.  So mixed
>>> gc is not keeping up.
>>>
>>> Can do a run keeping 16m region size,  no G1PrintRegionLivenessInfo, no
>>> PrintHeapAtGC.  But -XX:+G1SummarizeRSetStats
>>> -XX:G1SummarizeRSetStatsPeriod=10
>>>
>>> This should tell us more about RSet information.
>>>
>>> While the UpdateRS is not as bad as ScanRS, we can try to push it to the
>>> concurrent threads.  Can you add -XX:G1RSetUpdatingPauseTimePercent=5.  I
>>> am hoping this brings the UpdateRS down to 50ms.
>>>
>>>
>>> Thanks,
>>> Jenny
>>>
>>> On 7/28/2014 8:27 PM, Martin Makundi wrote:
>>>
>>>> Hi!
>>>>
>>>> We suffered a couple of Full GC's using regionsize 5M (it seems to be
>>>> exact looking at logged actual parameters) and we tried the 16M option and
>>>> this resulted in more severe Full GC behavior.
>>>>
>>>> Here is the promised log for 16 M setting:
>>>> http://81.22.250.165/log/gc-16m.log
>>>>
>>>> We switch back to 5M hoping it will behave more nicely.
>>>>
>>>> **
>>>> Martin
>>>>
>>>
>>>
>>
>>
>
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