Hi All, In our project we have a module, which will copy linux_mib structure to the userland. In userland I have constructed a similar structure to copy the values. If I try to use ____cacheline_aligned in the userland structure i get a compilation error. I am using Redhat Linux 8 with kernel version 2.4.18. The same code worked in earlier versions of Redhat Linux. I tried a sample program and have pasted it here //ct.c #include <linux/cache.h> struct test { int a; }____cacheline_aligned; int main() { return 0; } I tried compiling the above as follows gcc ct.c I get the following compilation error ct.c:6: `CONFIG_X86_L1_CACHE_SHIFT' undeclared here (not in a function) ct.c:6: requested alignment is not a constant Where I have went wrong? Thanks in advance, Regards, Mohan. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/