Hello Ralf, I made a patch for header file of 2.6. smp_processor_id() is defined in smp.h. We need adding #include <linux/smp.h> in processor.h. Please apply this patch. Yoichi diff -urN -X dontdiff linux-orig/include/asm-mips/processor.h linux/include/asm-mips/processor.h --- linux-orig/include/asm-mips/processor.h 2003-12-04 10:52:06.000000000 +0900 +++ linux/include/asm-mips/processor.h 2004-01-07 12:24:25.000000000 +0900 @@ -13,6 +13,7 @@ #include <linux/config.h> #include <linux/cache.h> +#include <linux/smp.h> #include <linux/threads.h> #include <asm/cachectl.h>