RFR: 8332516: Serial: Always sample promoted bytes to avoid getting stuck in Full GCs

[Albert Mingkun Yang]

On Mon, 20 May 2024 09:05:09 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Simple heuristic update around how promoted-bytes are tracked. The real change is in `TenuredGeneration::update_promote_stats`, which uses `used-old-gen` before/after gc to derived promoted-bytes.
> 
> The metric is imprecise in the cases of promotion-failure, because those should be rare. Also, after full-gc, used-old-gen an be decreased; in this case, we'd set promoted bytes as the min value (zero), the best-effort estimate.

Thanks for review.

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

PR Comment: https://git.openjdk.org/jdk/pull/19306#issuecomment-2154322558