Hi, I have applied the patch patch-2.6.21-rt8 to linux-2.6.21 with the command:patch < patch-2.6.21-rt8 -p1 Does any one have any idea on how to resolve this issue. I have very limited knowledge on data structures that is used. So, I'm reluctant to change any code. Please let me know if i'm missing some thing. In file included from include/linux/spinlock.h:100, from include/linux/signal.h:9, from arch/powerpc/kernel/asm-offsets.c:16: include/linux/spinlock_types.h:38: error: expected specifier-qualifier-list before '__raw_spinlock_t' include/linux/spinlock_types.h:49: error: conflicting types for 'raw_spinlock_t' include/linux/spinlock_types_up.h:25: error: previous declaration of 'raw_spinlock_t' was here include/linux/spinlock_types.h:54: error: expected specifier-qualifier-list before '__raw_rwlock_t' include/linux/spinlock_types.h:65: error: conflicting types for 'raw_rwlock_t' include/linux/spinlock_types_up.h:33: error: previous declaration of 'raw_rwlock_t' was here In file included from include/linux/signal.h:9, from arch/powerpc/kernel/asm-offsets.c:16: include/linux/spinlock.h: In function 'double_spin_lock': include/linux/spinlock.h:291: warning: implicit declaration of function '_spin_lock' include/linux/spinlock.h: In function 'raw_double_spin_unlock': include/linux/spinlock.h:312: warning: implicit declaration of function '_spin_unlock' In file included from include/linux/time.h:7, from include/linux/timex.h:57, from include/linux/sched.h:52, from arch/powerpc/kernel/asm-offsets.c:17: include/linux/seqlock.h: In function '__write_tryseqlock': include/linux/seqlock.h:102: warning: implicit declaration of function '_spin_trylock' include/linux/seqlock.h: In function '__read_seqretry': include/linux/seqlock.h:139: warning: implicit declaration of function '_spin_lock_irqsave' include/linux/seqlock.h:140: warning: implicit declaration of function '_spin_unlock_irqrestore' In file included from include/linux/fs.h:279, from include/linux/mm.h:15, from include/linux/mman.h:14, from arch/powerpc/kernel/asm-offsets.c:22: include/linux/lock_list.h: In function 'INIT_LOCK_LIST_HEAD': include/linux/lock_list.h:35: warning: implicit declaration of function 'spin_lock_init' -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html