RFR (S): Shortcut partial GC when no work expected

[Zhengyu Gu]

Good to me.

-Zhengyu

On 04/14/2017 08:14 AM, Aleksey Shipilev wrote:
> Hi,
>
> If we want to get partial as the default heuristics, then we better make sure it
> does not do redundant work. For example, if we have no candidate regions, it
> makes sense to shortcut the cycle:
>   http://cr.openjdk.java.net/~shade/shenandoah/partial-shortcut/webrev.01/
>
>
> Pause Partial GC (N)  =     0.07 s (a =     1503 us) (n =    45)
>     (lvls, us =      904,     1152,     1426,     1719,     2331)
>
> Pause Partial GC (N)  =     0.02 s (a =      517 us) (n =    43)
>     (lvls, us =      193,      344,      459,      666,      894)
>
> Thanks,
> -Aleksey
>