I have the following error when building sparc64 kernel on an AMD64/3.0 
system.

--- cpu.o ---
In file included from /stuff/src/sys/uvm/uvm_param.h:75,
                  from /stuff/src/sys/uvm/uvm_extern.h:482,
                  from /stuff/src/sys/arch/sparc64/sparc64/cpu.c:62:
/stuff/src/sys/sys/resourcevar.h:76: error: field 'p_slock' has incomplete 
type
/stuff/src/sys/sys/resourcevar.h:98: error: field 'ui_slock' has 
incomplete type
*** [cpu.o] Error code.

Just updated to the latest cvs and it's still failing with this same 
error.

-Ober