RFR (XS): -8064865: Remove the debug funciontality RotateCMSCollectionTypes for CMS
bengt.rutisson at oracle.com
Fri Nov 14 07:09:24 UTC 2014
On 2014-11-14 08:05, Bengt Rutisson wrote:
> Hi all,
> Can I have a couple of reviews for this small change to remove a debug
> flag from CMS?
I should have pointed out that this patch is based on top of the patch
for JDK-8064702 that is currently out for review.
> During the review of "8064702: Remove the CMS foreground collector" it
> was discussed how to handle the RotateCMSCollectionTypes feature. It
> was suggested to remove this feature in a separate change. This is the
> change to remove that feature.
> From the bug description:
> The RotateCMSCollectionTypes flag is used in CMS to rotate between the
> three different kinds of collections of the old generation that CMS
> has; background collection, foreground collection and full compacting
> serial GC.
> The functionality is only available in non-product builds.
> With JDK-8064702 the foreground collector is being removed. This means
> that there are only two types left. The RotateCMSCollectionTypes flag
> is not being automatically tested and it is very rarely used. Rather
> than maintaining it we should remove this functionality. If we need
> this for debugging in the future it is a pretty simple patch to add
> back. But for the most part it should be possible to debug in other
> ways, by for example using ExplicitGCInvokesConcurrent flag and similar.
More information about the hotspot-gc-dev