RFR: 8239825: G1: Simplify threshold test for mutator refinement

[Thomas Schatzl]

Hi,

On 04.03.20 03:16, Kim Barrett wrote:
> Please review this change to the handling of "padding" for the threshold
> used to decide whether a mutator thread should perform concurrent
> refinement.  Rather than doing a slightly tricky (because of potential
> overflow) computation every time a mutator thread completes a buffer,
> instead perform that computation once and record the result for repeated
> use.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8239825
> 
> Webrev:
> https://cr.openjdk.java.net/~kbarrett/8239825/open.00/
> 
> Testing:
> mach5 tier1-5 along with changes for JDK-8240133 and JDK-8139652.
> Local (linux-x64) hotspot:tier1 with just this change.
> 

   I think this is good.

Thomas