RFR: DRAFT: Expand old on demand [v42]

[Kelvin Nilsen]

On Wed, 10 May 2023 22:56:37 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

>> Kelvin Nilsen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix whitespace
>
> src/hotspot/share/gc/shenandoah/heuristics/shenandoahHeuristics.cpp line 133:
> 
>> 131:     }
>> 132:     if (r->age() >= InitialTenuringThreshold) {
>> 133:       r->save_top_before_promote();
> 
> We have to save top before promote, even if we do not  promote in place, because evacuator asks "what was garbage before top was saved"?  Need to think about tis...

the evacuator asks what was top at mark end?

-------------

PR Review Comment: https://git.openjdk.org/shenandoah/pull/248#discussion_r1190460033