Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 22 Apr 2024 20:11:59 +0100 | From | Matthew Wilcox <> | Subject | Re: [PATCH] mm: huge_memory: convert __do_huge_pmd_anonymous_page() to use folios |
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On Mon, Apr 22, 2024 at 11:12:16AM -0700, Jianfeng Wang wrote: > Change __do_huge_pmd_anonymous_page() to take folio as input, as its > caller has used folio. Save one unnecessary call to compound_head().
I don't like this patch. It makes the assumption that folios will never be larger than PMD size, and I don't think that's an assumption that's going to last another five years. Look where you had to do &folio->page:
> + clear_huge_page(&folio->page, vmf->address, HPAGE_PMD_NR);
> + entry = mk_huge_pmd(&folio->page, vma->vm_page_prot);
For mk_huge_pmd() in particular, you need to know the precise page, and not just use the first page of the folio.
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