Proposal: MaxTenuringThreshold and age field size changes

Tony Printezis tony.printezis at
Thu May 29 19:57:40 UTC 2008


Thomas Viessmann wrote:
> > If MTT is set by the user to a value > max age, we will actually set 
> it to max age.
> Agree. Still most customers use 32.
Even though they might use 32, it doesn't mean that the GC will actually 
use the "never tenure" policy. The actually tenuring threshold is 
actually auto-tuned by the GC so, if the GC notices that space in the 
survivor spaces is tight, it might lower the tenuring threshold 
irrespective of MTT. So, a lot of customers will get the autotuning 
policy if they set MTT to 32, not never tenure.
> Actually most if not all customers missed that change. I always see
> 32 or 0. Nothing in between.
Oh, I've seen lots in between. :-)


| Tony Printezis, Staff Engineer    | Sun Microsystems Inc.          |
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