RFR: 8276107: Preventive collections trigger before maxing out heap

[Stefan Johansson]

On Thu, 28 Oct 2021 16:09:36 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   can I have reviews for this small fix for an issue where preventive gcs that are supposed to prevent evacuation failure were also started if there were only not enough free committed regions available but more than enough uncommitted regions to expand the heap (to avoid the evacuation failure).
> 
> Testing: gha, tier1-3
> 
> Thanks,
>   Thomas

Looks good.  

I think we should also update the logging below to include `num_free_or_available_regions()` or maybe even better to just add available, but that would require a new getter if I'm not misstaken.

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Marked as reviewed by sjohanss (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/6160