why perm generation is continuously increasing?
alexey.ragozin at gmail.com
Thu Feb 16 22:00:50 PST 2012
Normally permanent generation is collect only during Full GC.
-XX:+CMSClassUnloadingEnabled will enable permanent space collection as a
part of concurrent old space collection.
Date: Thu, 16 Feb 2012 20:53:59 +0800
> From: Li Li <fancyerii at gmail.com>
> Subject: Re: why perm generation is continuously increasing?
> To: hotspot-gc-use <hotspot-gc-use at openjdk.java.net>
> <CAFAd71XuyVjQ+=0cTCpCB74wD03VgYe_GhgPj78mcU_pk3syaQ at mail.gmail.com
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> I got it. we use String.intern for temporary variables.
> I used jmap -permstat and found that.
> btw jmap -permstat will cause jvm hang and should be carefully used.
> it hangs for a few minutes!
> On Thu, Feb 16, 2012 at 6:55 PM, Li Li <fancyerii at gmail.com> wrote:
> > hi all,
> > I found our application's perm generation size is continuously
> > increasing and will reach 100%(we limit maxPermSize to 256MB) and
> perform a
> > full gc(which will pause for 10s).after gc, perm size usage falls to
> > 50% and again increasing. what kind of objects will be allocated to perm
> > generation? we don't use reflection in our application.
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