vmalloc() vs vmap()

Linux 2.6 also features a vmap( ) function, which maps page frames already allocated in a noncontiguous memory area: essentially, this function receives
as its parameter an array of pointers to page descriptors, invokes get_vm_area( ) to get a new vm_struct descriptor, and then invokes map_vm_area( ) to
map the page frames. The function is thus similar to vmalloc( ), but it does not allocate page frames.
也就是说vmap它将已经映射了的物理地址，又映射到了一些线性地址，所以对于这部分物理地址，现在有两个或两个以上的线性地址与其对应。
2009/02/05 四