Re: [patch 2/2] mspec driver

Jes Sorensen
2006-03-17T14:04:10Z

>>>>> "Nick" = Nick Piggin <nickpiggin@yahoo.com.au> writes:

Nick> Jes Sorensen wrote:
>> + vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP);

Nick> VM_PFNMAP actually has a fairly specific meaning [unlike the
Nick> rest of them :)] so you should be careful with it. Actually if
Nick> you set vm_pgoff in the right way, then that should enable you
Nick> to do COWs on these areas if that is what you want.

Yup, I went through that when I started using it. I think you guided
me through it :-)

We don't want COW here as the access is backed by special behavior in
the memory controller. We only allow shared mappings for that reason.

Cheers,
Jes