RFR (S): Update ShenandoahHeapRegionSampling protocol

[Roman Kennke]

Yes!

Does the sampling affect performance in any measurable way?

Roman

Am Mittwoch, den 01.02.2017, 11:56 +0100 schrieb Aleksey Shipilev:
> Hi,
> 
> I would like to update the ShenandoahHeapRegionSampling a bit:
>   http://cr.openjdk.java.net/~shade/shenandoah/sampling-update/webrev
> .01/
> 
> Changes:
>   *) Record and maintain "recently allocated" region flag
>   *) Steal more bits for region flags
>   *) Rehash the flags order
>   *) Coarsen region_size and used/live data to KB to make up for
> stolen bits
>   *) Update the sampling frequency to 40ms (25 FPS)
>   *) ShenandoahHR:is_pinned enabled to be read outside the safepoint
> 
> Testing: hotspot_gc_shenandoah
> 
> Thanks,
> -Aleksey
>