String Deduplication in JEP192

[Kirk Pepperdine]

On Mar 1, 2014, at 2:42 PM, charlie hunt <charlie.hunt at oracle.com> wrote:

> Hi Kirk,
> 
> Thanks for the good questions. :-)
> 
> At the risk of jumping in ahead of the JEP authors and reviewers ...
> 
> > where did you get the statistics from?
> 
> 900+ profiles

Customer apps I presume?

> 
> If you or others have a repository of profiles, (if can) please share your observations.

Sorry but I generally don’t keep customers code. ;-)

> 
> > If the weak generational hypothesis holds will you not be spending more time deduping soon to be garbage which potentially would place more load on the GC threads?
> 
> As mentioned in the JEP, you can manipulate the age at which a String becomes a candidate with -XX:StringDeduplicationAgeThreshold.

Missed that one.. I guess an obvious threshold would be a promotion to tenured????

I guess that only partially addresses the cost issues.

— Kirk