RFR (XS) 8230646: Epsilon does not extend TLABs to max size

[Aleksey Shipilev]

Thanks, pushed.

On 9/5/19 3:52 PM, Zhengyu Gu wrote:
> Looks good to me.
> 
> -Zhengyu
> 
> On 9/5/19 7:33 AM, Aleksey Shipilev wrote:
>> Bug:
>>    https://bugs.openjdk.java.net/browse/JDK-8230646
>>
>> I was playing with performance benchmarks and noticed that Epsilon does not extend issued TLABs to
>> max tlab size, because of the simple overlook. TLAB allocation path asks GC about the max tlab size
>> currently available with unsafe_max_tlab_alloc(). But, in Epsilon code, there is discrepancy: the
>> caller interprets the returned value in bytes, while Epsilon code has the size in words. Every other
>> GC adjusts accordingly, Epsilon should too.
>>
>> Fix:
>>    http://cr.openjdk.java.net/~shade/8230646/webrev.01/
>>
>> Testing: gc/epsilon, jdk-submit