RFR (S) 8233387: Shenandoah: passive mode should disable pacing ergonomically

[Zhengyu Gu]

Good to me.

-Zhengyu

On 11/1/19 10:06 AM, Aleksey Shipilev wrote:
> RFE:
>    https://bugs.openjdk.java.net/browse/JDK-8233387
> 
> This is the follow-up from JDK-8232791. There, we have added the ergonomic disable block in
> ShenandoahPassiveHeuristics. But, there is already the disable block in ShenandoahPassiveMode! In
> fact, it was there in ShenandoaPassiveHeuristics before introducing ShenandoahPassiveMode. We should
> revert JDK-8232791, and set the flag ergonomically in ShenandoahPassiveMode.
> 
> Fix:
>    https://cr.openjdk.java.net/~shade/8233387/webrev.01/
> 
> Testing: eyeballing GC logs, hotspot_gc_shenandoah
>