RFR: 8252221: Use multiple workers for Parallel GC pre-touching

[Amit Pawar]

On Fri, 9 Oct 2020 17:05:51 GMT, Amit Pawar <github.com+71302734+amitdpawar at openjdk.org> wrote:

>> Hi Thomas,
>> 
>> PR is updated with suggested changes. Please review.
>> 
>> Thanks,
>> Amit
>
> Hi Thomas,
> 
> I have fixed the build issue and also updated the PR with suggested changes. Thanks for testing and please check now.
> 
> Thanks,
> Amit

Hi Thomas,

Thanks for the your feedback and testing and good to hear that it passed 70%.

PR is updated as per your suggestions and please check.

I have another suggestion regarding "PreTouchParallelChunkSize" flag.
The default value looks huge and reducing this value to 128MB improved startup time for both G1GC and ParallelGC.
The following test are done with 1TB memory. Please see below.

ParallelGC = 0.5-1 sec.
G1GC = 2-3 sec

Also, the minimum value allowed is '1' and it should be similar to page size right ?

Please check.

Thanks,
Amit

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PR: https://git.openjdk.java.net/jdk/pull/180