As per the documentation( https://www.linuxjournal.com/article/6930 ), which says[emphasis mine]: Unfortunately for kernel developers, allocating memory in the kernel is not as simple as allocating memory in userspace. A number of factors contribute to the complication, among them: The kernel is limited to about 1GB of virtual and physical memory. **The kernel's memory is not pageable.** As per the documentation(https://www.oreilly.com <https://www.oreilly.com/library/view/linux-device-drivers/0596005903/ch08.ht...> /library/view/linux-device-drivers/0596005903/ch08.html <https://www.oreilly.com/library/view/linux-device-drivers/0596005903/ch08.ht...> ), which says: get_free_page and Friends If a module needs to allocate big chunks of memory, it is usually better to use a page-oriented technique. I am confused after I have seen these two sayings. I think they have the opposite meaning: the former one clams that the kernel's memory is not pageable whereas the latter one implicitly states there is a page-oriented technique used by the kernel(i.e. function get_free_page depends a page-oriented technique). I have thought and thought about it for a long time, but I still don't comprehend them.I would be grateful to have some help with this question. Thank you for your attention to this matter.