CRR: 7033292: G1: nightly failure: Non-dirty cards in region that should be dirty (XXS)

[Tony Printezis]

Thanks Ramki (and Igor)! All set. I'll push this asap (as soon as a job 
I currently have in the queue goes through).

Tony

Y. Srinivas Ramakrishna wrote:
> looks good.
>
> - ramki
>
> On 4/4/2011 8:23 AM, Tony Printezis wrote:
>> Tiny patch (only a single digit changed and a short comment added):
>>
>> http://cr.openjdk.java.net/~tonyp/7033292/webrev.0/
>>
>> The issue is that in the G1 card cache the epoch the cache entries 
>> are initialized to (e.g., 0) is
>> the same as what the current epoch is also initialized to. This makes 
>> the initialized, but not yet
>> populated, cache entries to look valid until the first GC. When one 
>> of those entries is replaced the
>> evicted card is incorrectly materialized to be the one that 
>> corresponds to the bottom of the heap.
>> The fix is to initialize the current epoch to 1 to automatically 
>> invalidate all the cache entries
>> that have not been populate yet.
>>
>> Many thanks to John Cuthbertson for his help on this.
>>
>> Tony
>