JEP 173: Remove Rarely-Used Combinations of Garbage Collectors

Bengt Rutisson bengt.rutisson at
Fri Dec 14 13:09:46 UTC 2012

Hi Richard and Andy,

Thanks for you feedback! Greatly appreciated!

Just to be clear. The JEP is not proposing to remove SerialOld. We are 
proposing to remove the ParNew+SerialOld combination. But the serial GC 
as in DefNew + SerialOld will still be there as well as the 
ParallelScavenge + SerialOld combination.


On 12/14/12 1:39 PM, lordpixel at wrote:
> On Dec 14, 2012, at 5:13 AM, Richard Warburton <richard.warburton at> wrote:
>> Furthermore Jack Shirazi pointed out that he was actually using SerialOld in some cases, and with a good tuning reason.  This isn't necessarily a good reason to keep SerialOld, but I'm trying to push back useful feedback.  Hope this is helpful.
> Another data point: we have 2 apps where we have used or considered using SerialOld because it is the only collector that will ever shrink the heap and give memory back to the hosting process. Both VMs are currently constrained to 32bit, one is desktop and one is embedded inside an older C++ program.
> AndyT (lordpixel - the cat who walks through walls)
> A little bigger on the inside
> 	(see you later space cowboy, you can't take the sky from me)

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