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

[Erik Osterlund]

Hi Per,

Looks good.

Thanks,
/Erik

> On 2 May 2019, at 10:26, Per Liden <per.liden at oracle.com> wrote:
> 
> 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