RFR (7xS): 8071280, 8162928, 8177707, 8177044, 8178148, 8175554, 8178151: Remembered set update/scan improvements

[Kim Barrett]

> On Apr 20, 2017, at 11:29 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
>> On Apr 11, 2017, at 7:30 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>> 
>> Hi all,
>> 
>>  I would like you to ask for reviews of a set of related changes that
>> optimize the way G1 updates/scans/refines cards of the remembered set.
>> 
>> […]
>> 8177707: Specialize G1RemSet::refine_card for concurrent/during
>> safepoint refinement
>> 
>> CR: https://bugs.openjdk.java.net/browse/JDK-8177707
>> Webrev: http://cr.openjdk.java.net/~tschatzl/8177707/webrev/
>> 
>> This change temporarily duplicates the code in G1RemSet::refine_card
>> for during refinement/gc to allow (initial) specialization of these
>> methods for their purpose.
> 
> src/share/vm/gc/g1/g1RemSet.cpp 
> 777   _conc_refine_cards++;
> 
> Since this is not in "concurrent" refinement, is it still correct to
> include it in this count?  Maybe the variable name is not right?  If
> so, I'd be okay with a variable rename in a later change if that makes
> management of this stack of changes easier.

And since you are in the neighborhood, consider adding a fix for
https://bugs.openjdk.java.net/browse/JDK-8043505
to this stack of changes.