RFR (S) 8245754: Shenandoah: ditch ShenandoahAlwaysPreTouch

[Roman Kennke]

Yes, makes sense and looks good!

Thanks,
Roman

On Mon, 2020-05-25 at 21:06 +0200, Aleksey Shipilev wrote:
> RFE:
>   https://bugs.openjdk.java.net/browse/JDK-8245754
> 
> ShenandoahAlwaysPreTouch flag dates back to the times when
> ShenandoahHeap used VirtualSpace for
> reserving/committing heap. To workaround single-threaded pretouch
> code in VirtualSpace, a new flag
> was needed:
>  
> https://mail.openjdk.java.net/pipermail/shenandoah-dev/2016-October/000892.html
> 
> That code is long gone now, and current Shenandoah just
> reserves/commits from OS directly.
> Therefore, this flag is no longer needed. It actually confuses
> logging in JDK-8245720.
> 
> Fix:
>   https://cr.openjdk.java.net/~shade/8245754/webrev.01/
> 
> Testing: hotspot_gc_shenandoah {fastdebug,release}; ad-hoc runs
>