Re: Problem with remap_page_range/mmap

Hugang
2004-03-26T10:00:14Z

On Fri, 26 Mar 2004 09:46:56 +0000
Christoph Hellwig <hch@infradead.org> wrote:

> On Fri, Mar 26, 2004 at 10:36:19AM +0100, Christian Leber wrote:
> > What would be the good idea? I need at least 8 at least 4MB (2MB are
> > enough for 2.4) big physical memory pieces for DMA, mapped to
> > userspace.
> >
> > remap_page_range for ia64.
>
> Put the page structs into an array and return them from ->nopage. The
> kernel pagefault code will set up the ptes for you.
>
> Now actually getting 4MB of continguous memory is a different issue..
>
> I'm surprised you actually managed to get the allocation to succeed.

There is more detailed information about make page usable to user space,
http://www.xml.com/ldd/chapter/book/ch13.html

Hope that's useful.

--
Hu Gang / Steve
Linux Registered User 204016
GPG Public Key: http://soulinfo.com/~hugang/hugang.asc