> I'm writing a kernel module in kernel 2.6.x. I called local_flush_tlb_all() in my module > and there is no error or warning during compiling time. you will not get the warnings during compilation because the function declaration would be visible (via a proper #include <foo.h>). > insmod: cannot insert `./mymodule.ko': Success (2): Success insmod, "fixes" up the references during module load time, and it complains that it cannot find the undefined symbol. look at /proc/kallsyms (assuming you are on a 2.6.X kernel) or /proc/ksys (if you are using 2.4) to see that your symbol exists here. one way to find out is to use objdump (or nm) to look at all the undefined symbols in your final kernel object. kind regards anupam -- if you need gmail invites, let me know ! -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/