RFR: 8359348: G1: Improve cpu usage measurements for heap sizing [v3]

[Man Cao]

On Wed, 30 Jul 2025 12:19:27 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Not a very realistic scenario, still I would prefer to not discount refinement costs...
> Maybe somehow separate marking and refinment cpu activity and merge again?

Fair enough. Perhaps we need to implement a metric that estimates how many refinement threads are active on average, between two pauses? So we don't overcount or undercount refinement cost.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/26351#discussion_r2243827378