Messages in this thread | | | Date | Mon, 23 Nov 2020 13:15:02 -0400 | From | Jason Gunthorpe <> | Subject | Re: Pinning ZONE_MOVABLE pages |
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On Mon, Nov 23, 2020 at 11:06:21AM -0500, Pavel Tatashin wrote:
> What I mean here is allowing users to guarantee that the page's PA is > going to stay the same. Sort of a stronger mlock. Mlock only > guarantees that the page is not swapped, but something like
You've just described get/pin_user_pages(), that is exactly what it is for.
I agree with the other emails, ZONE_MOVABLE needs to be reconciled with FOLL_LONGTERM - most likely by preventing ZONE_MOVABLE pages from being returned. This will need migration like CMA does and the point about faulting is only an optimization to prevent fault then immediate migration.
Jason
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