RFR(XXS) 8190729: Adjustment to anonymous metadata space chunk allocation algorithm

[Zhengyu Gu]

> 
> 
> 
> jtreg tests would be the most fitting. Quite easy to write actually. 
> Some examples are here:
> 
> /test/hotspot/jtreg/runtime/NMT/

Okay, I filed 8191931 (https://bugs.openjdk.java.net/browse/JDK-8191931) 
for the test.

Thanks,

-Zhengyu

> 
>     Updated webrev: http://cr.openjdk.java.net/~zgu/8190729/webrev.01/
>     <http://cr.openjdk.java.net/~zgu/8190729/webrev.01/>
> 
>     Thanks,
> 
>     -Zhengyu
> 
> 
> Thanks. To me, change looks good. No need for a new review.
> 
> ..Thomas
> 
> 
> 
>         Thank you,
> 
>         Kind Regards, Thomas
> 
> 
>         On Mon, Nov 27, 2017 at 6:09 PM, Zhengyu Gu <zgu at redhat.com
>         <mailto:zgu at redhat.com> <mailto:zgu at redhat.com
>         <mailto:zgu at redhat.com>>> wrote:
> 
>              Hi,
> 
>              To follow up recent discussion of anonymous metadata space
>         memory
>              usage, I would like submit this simple fix for review.
> 
>              By continuing allocating anonymous metadata space from
>              SpecializeChunk pool, up to 4 chunks, it reduces the waste
>         from 60+%
>              to about 30%.
> 
> 
>              Bug: https://bugs.openjdk.java.net/browse/JDK-8190729
>         <https://bugs.openjdk.java.net/browse/JDK-8190729>
>              <https://bugs.openjdk.java.net/browse/JDK-8190729
>         <https://bugs.openjdk.java.net/browse/JDK-8190729>>
>              Webrev: http://cr.openjdk.java.net/~zgu/8190729/webrev.00/
>         <http://cr.openjdk.java.net/~zgu/8190729/webrev.00/>
>              <http://cr.openjdk.java.net/~zgu/8190729/webrev.00/
>         <http://cr.openjdk.java.net/~zgu/8190729/webrev.00/>>
> 
>              Test:
> 
>                 hotspot_tier1_runtime on Linux x64 (fastdebug and release)
> 
> 
>              Thanks,
> 
>              -Zhengyu
> 
> 
>