RFR: Fix ShFreeSet boundary case

[Aleksey Shipilev]

On 05/10/2018 05:46 PM, Roman Kennke wrote:
> Am 10.05.2018 um 17:05 schrieb Aleksey Shipilev:
>> On 05/10/2018 04:42 PM, Aleksey Shipilev wrote:
>>> On 05/09/2018 09:30 PM, Roman Kennke wrote:
>>>> Observed with the new PLAB code. Apparently this triggers the situation fairly often because it
>>>> tends to allocate region sized GCLABs.
>> But this is also suspicious: we used to cap the TLAB sizes below region size to avoid fragmentation.
>> This does not happen with PLABs?
> 
> Apparently not.
> 
>> Should probably adjust that part.
> 
> Probably. I suggest to experiment with the new plab stuff once it's in
> and fine-tune it.

OK.

-Aleksey