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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 7F33340010 X-Rspamd-Server: rspam01 X-Stat-Signature: etaqdodyjj13q9u7p196pgwqc58wdkwu X-HE-Tag: 1726059947-627943 X-HE-Meta: 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 +eFR5yf5 Pil483OEUZ1QE0zW5L2OjccRvlYiuMYqnF8Q9UzSWvyERTDnb/8cCEU/F5ord0IXSoOm6eLWkCZZmYJnSy53txJmHKI/hPG2kpwkifE2KSiNQdIJtjI/MHDkzRmVjIog4zB8a7z3iLmoRa3bMgglzutSPR7883CDfPqlSTh2y4nIPLpM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/11/24 18:30, David Hildenbrand wrote: > On 11.09.24 14:53, Dev Jain wrote: >> >> On 9/11/24 14:57, David Hildenbrand wrote: >>> On 11.09.24 08:55, Dev Jain wrote: >>>> In preparation for the second patch, abstract away the THP allocation >>>> logic present in the create_huge_pmd() path, which corresponds to the >>>> faulting case when no page is present. >>>> >>>> There should be no functional change as a result of applying >>>> this patch. >>>> >>> >>> [...] >>> >>>> + >>>> +static void map_pmd_thp(struct folio *folio, struct vm_fault *vmf, >>>> +            struct vm_area_struct *vma, unsigned long haddr) >>>> +{ >>>> +    pmd_t entry; >>>> + >>>> +    entry = mk_huge_pmd(&folio->page, vma->vm_page_prot); >>>> +    entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); >>>> +    folio_add_new_anon_rmap(folio, vma, haddr, RMAP_EXCLUSIVE); >>>> +    folio_add_lru_vma(folio, vma); >>>> +    set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); >>>> +    update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); >>> >>> It's quite weird to see a mixture of haddr and vmf->address, and >>> likely this mixture is wrong or not not required. >>> >>> Looking at arc's update_mmu_cache_pmd() implementation, I cannot see >>> how passing in the unaligned address would do the right thing. But >>> maybe arc also doesn't trigger that code path ... who knows :) >> >> If I am reading correctly, arch/arc/mm/tlb.c: update_mmu_cache_pmd() >> calls update_mmu_cache_range() which is already expecting an unaligned >> address? But... > > So update_mmu_cache_pmd() calls > >     update_mmu_cache_range(NULL, vma, addr, &pte, HPAGE_PMD_NR); > > But update_mmu_cache_range() only aligns it *to page boundary*: > >     unsigned long vaddr = vaddr_unaligned & PAGE_MASK; Ah, totally missed that it was PAGE_MASK. Thanks. > > We obtain the correct hugepage-aligned physical address from the PTE > >     phys_addr_t paddr = pte_val(*ptep) & PAGE_MASK_PHYS; > > Then, we look at the offset in our folio > >     unsigned long offset = offset_in_folio(folio, paddr); > > And adjust both vaddr and paddr > >     paddr -= offset; >     vaddr -= offset; > > To then use that combination with > >     __inv_icache_pages(paddr, vaddr, nr); > > If I am not wrong, getting a non-hugepage aligned vaddr messes up > things here. But only regarding the icache I think. Looks like it... > >