RFR (S): JDK-8057910: G1: BOT verification should not pass top

[Thomas Schatzl]

Hi,

On Tue, 2014-09-09 at 14:13 +0200, Bengt Rutisson wrote:
> Hi all,
> 
> Can I have a couple of reviews for this fix?
> 
> http://cr.openjdk.java.net/~brutisso/8057910/webrev.00/
> 
> https://bugs.openjdk.java.net/browse/JDK-8057910
> 
> 
> After the fix for JDK-8025564 the BOT verification may pass the end for 
> the reserved space. The reason is this code in G1BlockOffsetArray::verify():
> 
>    size_t start_card = _array->index_for(gsp()->bottom());
>    size_t end_card = _array->index_for(gsp()->top());
> 
> The end_card should not be based on top() but on "top() - 1" to make 
> sure we are inside the heap region and thus inside the reserved space.
> 
> Testing:
> - Ad hoc aurora tests simulating nightly testing. The current bug failed 
> a lot in the nightly testing.
> - JPRT

  looks good.

Thomas