RFR: 8221359: Eliminate SATBMarkQueueSet::filter_thread_buffers

[Kim Barrett]

> On Apr 5, 2019, at 5:42 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi Kim,
> 
> On Mon, 2019-04-01 at 03:40 -0400, Kim Barrett wrote:
>> Please review this removal of the function used by G1 to clean up the
>> per-thread SATB queues when a young-only collection will have moved
>> young object references present in those queues.  This cleanup isn't
>> needed, since the same cleanup may be done before enqueuing a
>> completed queue buffer, and will also be done during the eventual
>> processing of the buffer contents.  Having this function called
>> during
>> a pause just moves some work from the concurrent phase into a pause,
>> which isn't a good tradeoff.
>> 
>> Also renamed G1GCPhaseTimes::ExtRootScanSubPhases(Start|End) =>
>> ExtRootScanSubPhases(First|Last), to remove the ambiguity over
>> whether
>> "end" is inclusive or exclusive.  (It was inclusive here.)
>> 
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8221359
>> 
>> Webrev:
>> http://cr.openjdk.java.net/~kbarrett/8221359/open.00/
>> 
> 
>  looks good.
> 
> Thanks,
>  Thomas

Thanks.