RFR (S): JEP-142: Reduce Cache Contention on Specified Fields

[Aleksey Shipilev]

On 11/24/2012 12:53 PM, Michael Barker wrote:
>>  -XX:FieldPaddingWidth=64:  3.55 +- 0.03 nsec/op
>>  -XX:FieldPaddingWidth=128: 3.54 +- 0.03 nsec/op
> 
> Do you have adjacent cache line prefetching supported/enabled?  These
> numbers suggest that padding to 2 cache lines doesn't provide a
> significant speed up over a single cache line.  If there isn't a large
> benefit to padding to 128 bytes, should be set as the default?

On my laptop this feature is disabled, so yes, padding for single cache
line already helps. On servers it's the whole different story, will do
some runs on larger machines later.

-Aleksey.