class metadata start and end address

Coleen Phillimore coleen.phillimore at
Thu Dec 20 08:36:56 PST 2012

On 12/19/2012 10:49 PM, Xin Tong wrote:
> Hi
> How can i get the Java class metadata start and end address in the hotspot VM ?

It depends on your configuration and version of Hotspot.   For jdk7 and 
below, the class metadata is in the Permgen, so Universe::print_on() 
will print these addresses.
After jdk7 and in hsx, the class metadata is class metaspace.  If you 
have UseCompressedKlassPointers on, this space is in a ReservedSpace 
below the Java heap (right now).   See Universe::reserve_heap().   If 
CompressedKlassPointers is false, a small space is allocated below the 
heap but it grows into mmap regions wherever the OS gives us these regions.


> Xin

More information about the hotspot-runtime-dev mailing list