Error message: "0-order allocation failed" ???

["Xiangfei Jia" <xjianz@xxxxxxxxx>]

I'm writing a kernel module. Most of the time, when I insert the module
into the kernel, I got the error messgage from the kernel saying:
__alloc_pages: 0-order allocation failed (gfp=0x20/0)

I think the error message says that there is not a single page to be
used for allocation. BUT, my module doesn't use a lot memory. I checked
the message usage after inserting the module, there are still more free
memory available. I'm quite confused what causes the problem. Can I get
some help to figure out the problem??

Thanks!!!

Fei