RFR: 8220411: Remove ScavengeRootsInCode=0 code

[Stefan Karlsson]

Hi Coleen,

Thanks for looking at this.

On 2019-03-11 14:19, coleen.phillimore at oracle.com wrote:
> 
> This is nice.  Shouldn't you remove ScavengeRootsInCode from 
> globals.hpp?  As a diagnostic command, I think it goes into the table in 
> arguments.cpp?

I left that part to be handled by JDK-8144954.

Thanks,
StefanK

> Thanks,
> Coleen
> 
> 
> On 3/11/19 6:26 AM, Stefan Karlsson wrote:
>> Updated webrev after some offline feedback from ErikÖ:
>>
>>  http://cr.openjdk.java.net/~stefank/8220411/webrev.02.delta
>>  http://cr.openjdk.java.net/~stefank/8220411/webrev.02
>>
>> - I've removed can_be_constant and updated the code where it was used.
>> - Removed and replaced check_oop with oopDesc::is_oop_or_null checks.
>>
>> Thanks,
>> StefanK
>>
>> On 2019-03-11 09:57, Stefan Karlsson wrote:
>>> Hi all,
>>>
>>> Please review this patch to remove code that checks and acts upon 
>>> ScavengeRootsInCode=0.
>>>
>>> http://cr.openjdk.java.net/~stefank/8220411/webrev.01/
>>> https://bugs.openjdk.java.net/browse/JDK-8220411
>>>
>>> Since a while now, we have not supported -XX:ScavengeRootsInCode=0, 
>>> and the code actively sets it to 1 if the user passes in 0. This 
>>> patch removes the actual code, there's another RFE to deal with 
>>> changing the argument handling to explicitly not support that the 
>>> flag is set to 0. See: JDK-8144954.
>>>
>>> My main motivation for this patch is to get rid of some of the usages 
>>> of CollectedHeap::is_scavengable. The intention is that later patches 
>>> will completely remove that function.
>>>
>>> Thanks,
>>> StefanK
>