Messages in this thread |  | | From | Jason Gunthorpe <> | Subject | Re: [RFC PATCH 3/5] mm/vma: add support for peer to peer to device vma | Date | Tue, 29 Jan 2019 20:58:35 +0000 |
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On Tue, Jan 29, 2019 at 01:39:49PM -0700, Logan Gunthorpe wrote:
> implement the mapping. And I don't think we should have 'special' vma's > for this (though we may need something to ensure we don't get mapping > requests mixed with different types of pages...).
I think Jerome explained the point here is to have a 'special vma' rather than a 'special struct page' as, really, we don't need a struct page at all to make this work.
If I recall your earlier attempts at adding struct page for BAR memory, it ran aground on issues related to O_DIRECT/sgls, etc, etc.
This does seem to avoid that pitfall entirely as we can never accidently get into the SGL system with this kind of memory or VMA?
Jason
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