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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kiryl Shutsemau , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: Content-Language: en-US From: Yin Tirui In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/21/26 02:07, Lorenzo Stoakes (Oracle) wrote: > +static bool has_deposited_pgtable(struct vm_area_struct *vma, pmd_t pmdval, > + struct folio *folio) > +{ > + /* Some architectures require unconditional depositing. */ > + if (arch_needs_pgtable_deposit()) > + return true; > + > + /* > + * Huge zero always deposited except for DAX which handles itself, see > + * set_huge_zero_folio(). > + */ > + if (is_huge_zero_pmd(pmdval)) > + return !vma_is_dax(vma); > + > + /* > + * Otherwise, only anonymous folios are deposited, see > + * __do_huge_pmd_anonymous_page(). > + */ > + return folio && folio_test_anon(folio); > +} Hi Lorenzo, I just wanted to mention a potential intersection with my upcoming v4 of the "mm: add huge pfnmap support for remap_pfn_range()" series [1]. To safely support PMD splitting on partial unmaps, my series makes VM_PFNMAP huge pages allocate and deposit page tables. However, they neither have an underlying struct folio nor are anonymous. Given the has_deposited_pgtable() helper, do you have any suggestions on what would be the cleanest way to integrate the VM_PFNMAP condition into it? [1] https://lore.kernel.org/linux-mm/20260228070906.1418911-5-yintirui@huawei.com/ -- Yin Tirui