Vassilis, you need to install sysprof-module-source and follow the instructions from /usr/share/doc/sysprof-module-source/README.Debian
You might also want to subscribe to bug #30160 which is about "support sysprof out of the box". -- sysprof lack application menu item https://launchpad.net/bugs/56599 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs