Messages in this thread | | | Date | Wed, 10 Sep 2008 12:55:25 +0300 | From | Avi Kivity <> | Subject | Re: [Xen-devel] Re: [PATCH 1 of 7] x86: add _PAGE_IOMAP pte flag for IO mappings |
| |
Avi Kivity wrote: >> >> I'm not sure; I still don't really understand how _PAGE_SPECIAL gets >> used, other than being user-mode mapping only. But in principle, >> _PAGE_IOMAP could be set on both kernel and user mappings (if you direct >> map a device into a process address space), so I think they would >> conflict then? >> >> > > It's a "don't refcount me" flag, which is not sematically the same as > I/O, but may be close enough.
Actually it's more of a "no struct page" flag, which implies no refcounting. And not having a struct page should correspond well to a pte not requiring pfn->mfn conversion and being an I/O page.
-- error compiling committee.c: too many arguments to function
| |