RFR: 8224666: Parallel GC: Use WorkGang (8: obsolete and remove flags)

[Kim Barrett]

> On May 29, 2019, at 8:55 AM, Leo Korinth <leo.korinth at oracle.com> wrote:
> 
> Hi,
> 
> Here is the eighth and last patch that removes gcTaskManager and uses
> the WorkGang abstraction instead.
> 
> This patch removes and obsoletes two product flags.
> 
> BindGCTaskThreadsToCPUs is used to run threads pinned on specific
> CPUs. Only implemented on Solaris and seems mostly unused.
> 
> UseGCTaskAffinity is used to take tasks with a certain thread
> affinity; it does not work and should have been obsoleted since (at
> least) JDK-8138707.
> 
> The code tries to obsolete BindGCTaskThreadsToCPUs and UseGCTaskAffinity
> in JDK 13. Push the removal _before_ next LTS(17); proposed removal is thus 16.
> 
> 
> Enhancement:
>  https://bugs.openjdk.java.net/browse/JDK-8224666
> 
> Webrev:
> http://cr.openjdk.java.net/~lkorinth/workgang/0/_8224666-Parallel-GC-Use-WorkGang-8-obsolete-and-remove-flags/
>  http://cr.openjdk.java.net/~lkorinth/workgang/0/all/
> 
> Testing (on the whole patch series):
>  mach5 remote-build-and-test --build-profiles linux-x64,linux-x64-debug,macosx-x64,solaris-sparcv9,windows-x64 --test open/test/hotspot/jtreg/:hotspot_gc -a -XX:+UseParallelGC
>  gc test suite
> 
> Thanks,
> Leo

8224666-Parallel-GC-Use-WorkGang-8-obsolete-and-remove-flags
8224666-Parallel-GC-Use-WorkGang-8-obsolete-and-remove-flags-fixup-1

Looks good.

I see there is a draft CSR for removal of these product flags
(JDK-8224668).  I think it needs to be pushed along in the state
machine so it can be reviewed.  I've reviewed the current text and it
looks okay to me.