linux kernel development (12 Memory Management)

Yo u c a n n o t s p e c i f y __GFP_HIGHMEM  to either __get_free_pages()  or kmalloc().
Because these both return a logical address, and not a page  structure, it is possible that
these functions would allocate memory not currently mapped in the kernel’s virtual
address space and, thus, does not have a logical address. Only alloc_pages()  can allocate
high memory.The majority of your allocations, however, will not specify a zone modifier
because ZONE_NORMAL  is sufficient

http://comments.gmane.org/gmane.linux.ports.arm.kernel/96732

原文地址:https://www.cnblogs.com/cute/p/2084305.html