Hi Leo,
cc'ing build-dev. I think there is a process you need to follow to
remove VM features from the build system. And build folk need to check
all build changes anyway.
Thanks,
David
On 18/10/2019 6:20 pm, Leo Korinth wrote:
Hi,
Here is a patch that removes the CMS GC.
I have neither tested arm nor ppc; I hope my changes to those .ad files
are correct, if someone can test those architectures, that would be great.
Please take an extra look at
CollectedHeap::check_for_non_bad_heap_word_value, it was buggy before
(but never called), It is now called (and hopefully correct).
I have tried to remove most parts of CMS. I have not made it a goal to
remove all traces of CMS. I guess there are much more to cleanup, and
suggestions of more to remove are welcomed. I think more complicated
cleanups should be dealt with in separate enhancements.
Not fully addressed in code, but an issue that has to be dealt with, how
do I obsolete -Xconcgc and -Xnoconcgc? I believe the option should be
obsoleted, though I do not know if we have any precedence obsoleting -X
options.
My patch prints:
$ java -Xconcgc -jar Notepad.jar
Java HotSpot(TM) 64-Bit Server VM warning: -Xconcgc uses UseConcMarkSweepGC
I guess that is not enough for being obsolete, compare with:
$ java -XX:UseConcMarkSweepGC -jar Notepad.jar
Java HotSpot(TM) 64-Bit Server VM warning: Ignoring option
UseConcMarkSweepGC; support was removed in 14.0
Bug:
https://bugs.openjdk.java.net/browse/JDK-8232365
Webrev:
http://cr.openjdk.java.net/~lkorinth/8232365/00
Testing:
tier 1-5.
Thanks,
Leo
