Messages in this thread | | | From | Ingo Oeser <> | Subject | Re: User switchable HW mappings & cie | Date | Mon, 9 Oct 2006 20:36:47 +0200 |
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Hi all,
On Monday, 9. October 2006 13:51, Benjamin Herrenschmidt wrote: > > One problem that occurs is that the rule for ptes with non-backing > > struct pages > > Which I think was introduced in 2.6.16: > > > > pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT) > > > > cannot be honored, at least not with the DRM memory manager, since the > > graphics object will be associated with a vma and not the underlying > > physical address. User space will have vma->vm_pgoff as a handle to the > > object, which may move around in graphics memory. > > That's a problem with VM_PFNMAP set indeed. get_user_pages() is a > non-issue with VM_IO set too but I'm not sure about other code path that > might try to hit here... though I think we don't hit that if MAP_SHARED, > Nick ?
Istn't this just a non-linear PFN mapping, you are describing here?
Nick: Cant your new fault consolidation code handle that? AFAICS your new .fault handler just gets the vma and pgoff and install the matching PTE via install_THINGIE() or vm_insert_THINGIE()
Or do I miss sth. here?
Regards
Ingo Oeser - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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