linux user group brescia

Ho provato a compilare il kernel 2.4.21-pre5, ma il processo mi da subito 
questo errore:

make CFLAGS="-D__KERNEL__ -I/usr/src/kernel-source-2.4.21-pre5/include -Wall 
-Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common 
-fomit-frame-pointer -pipe -mpreferred-stack-boundary=2 -march=athlon " -C  
kernel
make[1]: Entering directory `/usr/src/kernel-source-2.4.21-pre5/kernel'
make all_targets
make[2]: Entering directory `/usr/src/kernel-source-2.4.21-pre5/kernel'
gcc -D__KERNEL__ -I/usr/src/kernel-source-2.4.21-pre5/include -Wall 
-Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common 
-fomit-frame-pointer -pipe -mpreferred-stack-boundary=2 -march=athlon   
-nostdinc -iwithprefix include -DKBUILD_BASENAME=sched  
-fno-omit-frame-pointer -c -o sched.o sched.c
sched.c: In function `reschedule_idle':
sched.c:228: warning: implicit declaration of function `TASK_SUSPENDED'
sched.c: At top level:
sched.c:909: redefinition of `set_cpus_allowed'
sched.c:870: `set_cpus_allowed' previously defined here
make[2]: *** [sched.o] Error 1
make[2]: Leaving directory `/usr/src/kernel-source-2.4.21-pre5/kernel'
make[1]: *** [first_rule] Error 2
make[1]: Leaving directory `/usr/src/kernel-source-2.4.21-pre5/kernel'
make: *** [_dir_kernel] Error 2

dove sto sbagliando ???