I get this build error with current -git on x86_64 (config attached):

   CC      arch/x86/kernel/kgdb.o
arch/x86/kernel/kgdb.c:52:28: error: asm/mach_apic.h: No such file or 
directory
arch/x86/kernel/kgdb.c: In function 'kgdb_roundup_cpus':
arch/x86/kernel/kgdb.c:337: error: implicit declaration of function 
'send_IPI_allbutself'
make[1]: *** [arch/x86/kernel/kgdb.o] Error 1
make: *** [arch/x86/kernel] Error 2