G1gc compaction algorithm

[Martin Makundi]

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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