CRR (XXS): 7146246: G1: expose some of the -XX flags that drive which old regions to collect during mixed GCs

[Tony Printezis]

Thanks John!

On 03/21/2012 04:32 PM, John Cuthbertson wrote:
> Hi Tony,
>
> Looks good to me. I like the new names.
>
> JohnC
>
> On 03/21/12 08:13, Tony Printezis wrote:
>> Hi all,
>>
>> Can I have a couple of quick code review for this very small change?
>>
>> http://cr.openjdk.java.net/~tonyp/7146246/webrev.0/
>>
>> It turns the following two cmd line params into product params:
>>
>> G1HeapWastePercent (previously called: G1OldReclaimableThresholdPercent)
>> G1MixedGCCountTarget (previous called: G1MaxMixedGCNum)
>>
>> These are helpful in allowing the user to fine-tune G1's behavior wrt 
>> which old regions to collect during mixed GCs, how many mixed GCs to 
>> do, etc.
>>
>> I also increased the default value of the former from 1% to 5%. 
>> Charlie ran some performance tests and found that the new default 
>> eliminated some very long mixed GCs that he was experiencing with the 
>> old default.
>>
>> Tony
>>
>