Integrated: 8318201: GenShen: Remove preparatory young GC before bootstrap

[Kelvin Nilsen]

On Fri, 13 Oct 2023 15:14:15 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

> We currently precede every old-mark bootstrap gc with a young gc.  The intent was to replenish the young allocation pool before beginning the "long" coalesce-and-fill effort which is part of the bootstrap gc.  This current design is mis-guided because the coalesce-and-fill effort will be preempted if a young gc is triggered while we are working on coalesce-and-fill.
> 
> This PR has the potential of reducing the number of concurrent young gcs by the number of times we initiate an old bootstrap gcs.

I'll leave this in draft mode until we pass tests.  I'll associate with a JBS ticket when I mark read to review.

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

PR Comment: https://git.openjdk.org/shenandoah/pull/340#issuecomment-1761686181