Messages in this thread | | | Date | Thu, 17 Sep 2020 17:40:59 -0400 | From | Peter Xu <> | Subject | Re: [PATCH 1/4] mm: Trial do_wp_page() simplification |
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On Thu, Sep 17, 2020 at 01:35:56PM -0700, Linus Torvalds wrote: > For that to happen, we'd need to have the vma flag so that we wouldn't > have any worry about non-pinners, but as you suggested, I think even > just a mm-wide counter - or flag - to deal with the fast-bup case is > likely perfectly sufficient.
Would mm_struct.pinned_vm suffice?
Though now I'm not 100% certain whether all pin_user_pages*() callers are accounting correctly upon pinned_vm. My gut feeling is that bc3e53f682d93df67 does not convert all the old locked_vm users with page pinnings (e.g., mm_iommu_do_alloc, vaddr_get_pfn, etc.; didn't try harder).
-- Peter Xu
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