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

[Thomas Schatzl]

Hi Amit,

On 09.10.20 19:08, Amit Pawar wrote:
> On Tue, 6 Oct 2020 18:11:52 GMT, Amit Pawar <github.com+71302734+amitdpawar at openjdk.org> wrote:
> 
>>> Thanks for agreeing and will update the PR with suggested changes for final review.
>>>
>>> Thanks,
>>> Amit
>>
>> 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
> 

   thanks for your changes. Some more, final minor nits:

- mutableSpace.cpp:115: please remove the newline after the "if"

- psYoungGen.cpp:641: I do not think PSYoungGen::resize_spaces() can be 
called by anything but the VMThread, so code to distinguish there seems 
superfluous.

I.e. ultimately by either PSParallelCompact::invoke_no_policy() or 
PSScavenge::invoke_no_policy.

Same with the code in PSYoungGen::reset_survivors_after_shrink().

(I did not actually test this change).

- preTouchTask.hpp: please move all implementation to the cpp file, then 
you can also move all includes to that file. (Do not forget the forward 
declaration of WorkGang).

- preTouchTask.hpp: please drop the first "private:" in the PretouchTask 
class.

- preTouchTask.hpp: please move the "size_t page_size" for the static 
pretouch method to the next line.

- preTouchTask.hpp:56: please drop the extra spaces between function 
declaration and definition of chunk_size().

- preTouchTask.cpp: please add "#include "precompiled.hpp"" as first 
includes. Otherwise it will not build on Windows.

Other than that testing tiers 1-5 seems good so far (70% done) after 
fixing the precompiled.hpp issue.

Thanks,
   Thomas