RFR: Use PLAB for evacuations instead of TLAB

[Roman Kennke]

Am 11.05.2018 um 22:37 schrieb Aleksey Shipilev:
> On 05/11/2018 10:31 PM, Roman Kennke wrote:
>> Differential patch:
>> http://cr.openjdk.java.net/~rkennke/plab-gclab/webrev.04.diff/
>> Full patch:
>> http://cr.openjdk.java.net/~rkennke/plab-gclab/webrev.04/
>>
>> Ok?
> 
> OK. "obj1" might use a better name, e.g. "head_obj"?

Ok, done that.

> A bit sad we need to call post-alloc setup for fillers. We should maybe revisit this places some
> time later, and split the paths with UseShenandoahGC.

It's basically what we did in TLABs. It'll all go away and look much
nicer with the allocation refactoring!

Diff:
http://cr.openjdk.java.net/~rkennke/plab-gclab/webrev.05.diff/
Full:
http://cr.openjdk.java.net/~rkennke/plab-gclab/webrev.05/

Ok?