Integrated: 8316299: GenShen: Reduce frequency of expedited GC

[Kelvin Nilsen]

On Thu, 14 Sep 2023 15:21:53 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

> We have found that expedited GCs too frequently yield very little benefit because they occur so soon after the previous GC that there has been no accumulation of garbage.
> 
> The primary motivation for expediting GC is to avoid a situation under which there is so much "promotion" work to be performed that the urgent need to reclaim garbage from young-generation is obstructed by this promotion work.
> 
> This PR ends the practice of expediting to support promotion in place.  The effort required to promote a region in place is minimal and unlikely to contend in a major way with young collection efforts.
> 
> This PR also reduces the likelihood that we will expedite for promotion by evacuation, because it requires the amount of accumulated promo potential to exceed a particular threshold.

This pull request has now been integrated.

Changeset: aa1063ff
Author:    Kelvin Nilsen <kdnilsen at openjdk.org>
URL:       https://git.openjdk.org/shenandoah/commit/aa1063ff5eac93b2ddf71f3ef71cb4ea92521427
Stats:     31 lines in 6 files changed: 2 ins; 28 del; 1 mod

8316299: GenShen: Reduce frequency of expedited GC

Reviewed-by: shade, wkemper

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PR: https://git.openjdk.org/shenandoah/pull/325