Default [Q] Android process memory dump - gcore error

I am using gdb for dumping core file for an android process. I am running gdbserver on the device on tcp port and gdb client on the desktop. When i do gcore on client i get the below error. Does any one know why i'm getting this error ? any help much appreciated.

(gdb) gcore
Command not implemented for this target.

The reason i'm doing this to dump process memory and extract Classes.dex file from the memory using core file. I've tried doing this using /proc/pid/mem and proc/pid/maps and dump memory but that has too many mapped regions , i couldn't find the area where the Classes.dex file is. Any other alternate approach is also welcome. Thanks for your help