RFR 8035735: Metaspace::contains become extremely slow in some cases

Jon Masamitsu jon.masamitsu at oracle.com
Fri Feb 28 14:33:00 PST 2014

On 2/28/2014 1:57 PM, Coleen Phillimore wrote:
> On 2/28/2014 4:48 PM, Jon Masamitsu wrote:
>> Coleen,
>> You're casting something to a Method*, right?  Is
>> that assert ever going to fail?
> It's not going to fail the assert, but it might crash trying to access 
> the Metadata vtable if it's not metadata.   I debated this with myself 
> - would we rather have a SEGV there or no assert at all and some 
> problem later on?  We don't have a faster way to check whether 
> somethings in the metaspace that is safe from CMS deleting mmap 
> regions while we look at them.

Ok.  Looks good then.

> Coleen
>> Jon
>> On 2/28/2014 12:08 PM, Coleen Phillimore wrote:
>>> Summary: Call is_metadata instead which does less work for the call 
>>> in debugInfo.hpp which is called for all compiled code stack frames.
>>> open webrev at http://cr.openjdk.java.net/~coleenp/8035735/
>>> bug link https://bugs.openjdk.java.net/browse/JDK-8035735
>>> Tested with failing test case, nsk.quick.testlist, jcks and jtreg 
>>> tests.
>>> Coleen

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