Support for SoftMaxHeapSize?

[Holger Hoffstätte]

On 2020-09-01 16:32, Aleksey Shipilev wrote:
> On 8/28/20 12:41 PM, Holger Hoffstätte wrote:
>> I've been playing with setting SoftMaxHeapSize for ZGC in order to limit its
>> somewhat eager hunger for heap, and it does a really great job while still
>> allowing heap expansion for bursty LDS. Would this make sense for Shenandoah as
>> well? Compact mode does a great job already, but IMHO some conceptual feature
>> parity wouldn't hurt. Only if it's possible and not too much work, obviously. :)
> 
> It does not seem to be much work, as we need to do two things: make
> heuristics target the soft-max and teach uncommit code to favor new
> target when it changes.

Thought so :)

> 
> Prototyping here:
>    https://bugs.openjdk.java.net/browse/JDK-8252660
> 

That was quick.. :D

Tried with 14.0.2 (since I still had the tarball), patch applied and built
cleanly. For a quick test I ran eclipse (Shenandoah completely with default
options), opening/building several projects, CDT indexer, plugin updates,
marketplace etc. & watching in JMC.

We can haz pictures: https://imgur.com/a/hW4IYQq

Very nice and (to me) exactly as expected. Thanks!

Holger