RFR: 8222480: Implementation: JEP 351: ZGC: Uncommit Unused Memory

[Per Liden]

Hi,

Some additional refinements and rebased on the latest jdk/jdk. I'm 
hoping this is the last revision.

Testing: Passed tier 1-6

Diff: http://cr.openjdk.java.net/~pliden/8222480/webrev.3-diff
Full: http://cr.openjdk.java.net/~pliden/8222480/webrev.3

/Per

On 4/25/19 4:07 PM, Per Liden wrote:
> Hi,
> 
> Additional performance testing uncovered a regression in the allocation 
> path, due to the removal of the ZPreMapped class. This was fixed, by 
> priming the page cache with the initial heap size, and allowing the page 
> cache to split pages. This also helps avoid a certain class of page 
> cache evictions, where we can simply split a page instead.
> 
> Diff: http://cr.openjdk.java.net/~pliden/8222480/webrev.2-diff
> Full: http://cr.openjdk.java.net/~pliden/8222480/webrev.2
> 
> cheers,
> Per
> 
> On 4/23/19 3:26 PM, Per Liden wrote:
>> Hi,
>>
>> I sat down with Stefan to review this. A few adjustments where made.
>>
>> Updated webrev:
>>
>> Diff: http://cr.openjdk.java.net/~pliden/8222480/webrev.1-diff
>> Full: http://cr.openjdk.java.net/~pliden/8222480/webrev.1
>>
>> /Per
>>
>> On 4/15/19 11:34 AM, Per Liden wrote:
>>> Please review the implementation for JEP 351: ZGC: Uncommit Unused 
>>> Memory.
>>>
>>> Once the review has been completed, I intend to move the JEP to 
>>> Proposed To Target for JDK 13.
>>>
>>> The JEP has been updated to reflect the latest state of the 
>>> implementation.
>>>
>>> Testing: Passes tier1-3 on all Oracle platformsm and tier1-7 on 
>>> Linux/x86_64.
>>>
>>> JEP: https://bugs.openjdk.java.net/browse/JDK-8220347
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8222480
>>> Webrev: http://cr.openjdk.java.net/~pliden/8222480/webrev.0
>>>
>>> /Per