RFR JDK-8194084: Obsolete FastTLABRefill and remove the related code

[JC Beyler]

Answering all in one go :)

I updated the webrev to:
http://cr.openjdk.java.net/~jcbeyler/8194084/webrev.01/

I am guessing I need a tested ok from each architecture and not only a
looks good. If I am wrong, I apologize! If I am right, the current status
of each architecture is:

- aarch64: I removed the use of r5 but left for now r19 to be stored/loaded
back, let me know what you think, Derek.
- ppc64 and s390 look good  from Martin, missing a tested ok
- Sparc looks good from Coleen, missing a tested ok
    - I removed the option from globals.h, let me know if that is correct,
it seems to be what is said from the comment above but I thought maybe we
had to wait until the version number got bumped and then move all flags out
of globals.hpp.

- arm: missing a looks good and test
- x86: missing a looks good and test :)

I'm happy to do as I did with
https://bugs.openjdk.java.net/browse/JDK-8190862 and create subtasks if
that will make it easier on everyone.

Let me know,
Jc


On Fri, Feb 16, 2018 at 5:49 AM, <coleen.phillimore at oracle.com> wrote:

>
> I agree with this change, and will sponsor it and test on sparc (and on
> oracle platforms).
>
> When you obsolete an option, I think you just remove it from globals.hpp
> and the code in arguments.cpp should tell you it's obsolete.
>
> Thanks,
> Coleen
>
> On 2/14/18 6:08 PM, JC Beyler wrote:
>
>> Hi all,
>>
>> Here is a webrev to do the work mentioned in JDK-8194084
>> <https://bugs.openjdk.java.net/browse/JDK-8194084>:
>> http://cr.openjdk.java.net/~jcbeyler/8194084/webrev.01/
>>
>> It has the parts for each architecture and I can't test a lot of them so I
>> would need a review and test for each :). I think first would be an
>> agreement to the code change itself then test it once everyone agrees on
>> the change ?
>>
>> Could I please get some initial reviews on this?
>>
>> Basically what this webrev does is follow what the interpreter is saying:
>>    - No longer try to do a fast tlab refill
>>    - Try eden allocation if contiguous inline allocation is true
>>    - Otherwise slowpath
>>
>> This is true for all architectures except:
>>     - ppc, which doesn't do eden allocations, I just cleaned up the code a
>> bit there to be consistent
>>     - s390 that does not do tlab_refill at all, I just removed the dead
>> code
>> there.
>>
>> Thanks a lot for your help,
>> Jc
>>
>
>