> Why is kernel restricted to use virtual addresses of only 1 GB? Or > what is the need to split up the virtual address space into user > addresses and kernel addresses? We can have 4GB for kernel and 4GB for userspace but this has a overhead of flushing of tlb for every syscall. You can also make the split 2/2GB but this has a problem of having less user address space. 3/1 is a better choice. -- Vivek Kutal - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs