Request for review (xs) - 8000325

Jon Masamitsu jon.masamitsu at
Fri Jan 4 23:23:59 UTC 2013

On 11/29/2012 3:17 PM, Srinivas Ramakrishna wrote:
> Looks good. Would be great to prominently release-note this change when it
> appears in a public/GA update/release.
> Out of curiosity, any perf data on CMS pause time diffs from this change
> with current NPG?

I ran refworkload server_reference and saw a regression only on 
specjbb2000.  The regression was on the
remark pauses (as would be expected) and the largest I saw was about 
12%.  Larger than I would have
hoped.   The unloading is done serially so maybe things around it got 


> -- ramki
> On Thu, Nov 29, 2012 at 9:46 AM, Jon Masamitsu<jon.masamitsu at>wrote:
>> This is a change in the default class unloading policy for CMS.
>> 8000325:        Change default for CMSClassUnloadingEnabled to true
>> With perm gen removal it becomes important for CMS to unload
>> classes to avoid excessive consumption of native memory for
>> metadata.

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