Perf Impact of CMSClassUnloadingEnabled
Andreas.Loew at oracle.com
Mon Nov 7 10:33:17 PST 2011
sorry, a follow-up question from my side: As it shouldn't be the most
normal thing even for a Java EE app to constantly dereference
classloaders or single classes that need to be GC'ed:
In how far does your statement about increased remark pauses still apply
in case the PermGen / set of loaded classes has stayed completely
constant between initial mark and remark (which should be the usual case)?
And wouldn't there a also be a distinction between PermGen and Old Gen?
Many thanks & best regards,
Senior Java Architect
Oracle Advanced Customer Services Germany
Am 07.11.2011 16:44, schrieb Jon Masamitsu:
> Doing class unloading with CMS will often increase the remark pause times
> and so is not on by default.
> On 11/5/2011 3:29 PM, Martin Hare Robertson wrote:
>> I recently encountered an interesting GC issue with a Tomcat application. I
>> came up with a simple repro scenario which I posted to StackOverflow:
>> To solve this issue I have been encouraged to use
>> I currently use the following GC configuration.
>> Is enabling CMSClassUnloadingEnabled likely to have a negative perf impact?
>> If not, why is it disabled by default?
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