i am trying to write a module for which i have to use some kernel functions like rdtscl() , udelay() etc. i'm running redhat 9.0 (kernel 2.4.20-6) what is the difference between the header files of /usr/include and /usr/src/linux-2.4.20/include/ some functions are missing in the headers of /usr/include but are present in /usr/src/linux-2.4.20/include/ how to solve this problem. __________________________________ Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger. http://messenger.yahoo.com/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/