RFR (T): 8213997: Remove G1HRRSUseSparseTable flag

[Man Cao]

Looks good to me, too. (I'm not a reviewer, though.)

-Man

On Fri, Nov 16, 2018 at 6:10 AM Thomas Schatzl
<thomas.schatzl at oracle.com> wrote:
>
> Hi all,
>
>   can I have reviews to remove the G1HRRSUseSparseTable develop flag?
>
> It has never been used to my recollection, and if so only for doing
> performance comparisons.
>
> However in that case you need a modified build anyway as it is a
> develop flag, i.e. you already need to modify the code.
>
> Even if you disable Sparse PRTs you still pay some memory costs, so it
> does not allow easy memory comparisons anyway.
>
> From performance/memory consumption POV sparse PRTs are always a win,
> in some cases we even recommend to let G1 store more remembered set
> entries in sparse PRTs to save memory (without otherwise adverse
> effects).
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8213997
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8213997/webrev/
> Testing:
> local compilation
>
> I consider this change trivial as it consists of code deletion and some
> reformatting only.
>
> Thanks,
>   Thomas
>
>