RFR (M): 8227739: Merge cost predictions for scanning cards and log buffer entries

[Stefan Johansson]

> 28 nov. 2019 kl. 20:22 skrev Kim Barrett <kim.barrett at oracle.com>:
> 
>> On Nov 28, 2019, at 6:13 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>> 
>> http://cr.openjdk.java.net/~tschatzl/8227739/webrev.1_to_2/ (diff)
>> http://cr.openjdk.java.net/~tschatzl/8227739/webrev.2/ (full)
>> 
>> Thanks,
>> Thomas
> 
> ------------------------------------------------------------------------------
> src/hotspot/share/gc/g1/g1HotCardCache.cpp
>  74   // This does not need an atomic update. Racing threads may at most write the
>  75   // same value.
>  76   if (index == _hot_cache_size) {
>  77     Atomic::store(&_cache_wrapped_around, true);
> 
> That comment seems like it has some wording problems. It's also about
> the store, so perhaps should be between lines 76 and 77. Maybe reword
> something like
> 
> Can use relaxed store because all racing threads are writing the same
> value and there aren't any concurrent readers.
> ------------------------------------------------------------------------------
> 
> Looks good.  I don't need a new webrev for futzing with the comment.
> 

Looks good to me to and no need for further webrevs.

Stefan