Request for code review - JDK-8141123 Change int's to size_t in FreeIdSet

[Kim Barrett]

On Dec 2, 2015, at 4:44 PM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> On Wed, 2015-12-02 at 16:08 -0500, Kim Barrett wrote:
>> Attempting to eliminate FreeIdSet certainly has appeal.  However, I
>> don't have any intuition about the importance of the FromCardCache,
> 
> The fromcardcache caches for every combination of thread id and region
> which card has most recently been added to the remembered set.
> 
> It purely acts as a filter of repeated attempts to add the same card by
> the same thread to the remembered set. It seems to be quite effective at
> doing so in many cases.

That confirms my understanding of what it does.  Thanks.

It helps when several locations covered by a card refer to objects
that are in the same region.  And that does seem like a common case.

We can take further discussion elsewhere and let this review thread be
closed out.