> > $ gcc acct.c -o ac > acct.c:46: fatal error: linux/mm.h: No such file or directory > compilation terminated. > That is because gcc does not know where to look for the included mm.h-file, the gcc compiler needs to be specifically told where to look for include files if they are not in the standard directories. You can do that by passing it the -I option followed by the directory to look in.