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[2003:cb:c738:3100:8133:26cf:7877:94aa]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-38a8e38c006sm15191889f8f.46.2025.01.14.08.40.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Jan 2025 08:40:38 -0800 (PST) Message-ID: <31919e6c-0cec-4e3a-a0c6-a80be53d6ccc@redhat.com> Date: Tue, 14 Jan 2025 17:40:35 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 16/26] huge_memory: Add vmf_insert_folio_pmd() To: Alistair Popple , akpm@linux-foundation.org, dan.j.williams@intel.com, linux-mm@kvack.org Cc: alison.schofield@intel.com, lina@asahilina.net, zhang.lyra@gmail.com, gerald.schaefer@linux.ibm.com, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, dave.hansen@linux.intel.com, ira.weiny@intel.com, willy@infradead.org, djwong@kernel.org, tytso@mit.edu, linmiaohe@huawei.com, peterx@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com, chenhuacai@kernel.org, kernel@xen0n.name, loongarch@lists.linux.dev References: <02216c30a733ecc84951f9aeb1130cef7497125d.1736488799.git-series.apopple@nvidia.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 833842000E X-Stat-Signature: x8hsb6oazfrcypddyhpn3tounntybfti X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1736872844-198630 X-HE-Meta: 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 47AJQyhP 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 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: > +vm_fault_t vmf_insert_folio_pmd(struct vm_fault *vmf, struct folio *folio, bool write) > +{ > + struct vm_area_struct *vma = vmf->vma; > + unsigned long addr = vmf->address & PMD_MASK; > + struct mm_struct *mm = vma->vm_mm; > + spinlock_t *ptl; > + pgtable_t pgtable = NULL; > + > + if (addr < vma->vm_start || addr >= vma->vm_end) > + return VM_FAULT_SIGBUS; > + > + if (WARN_ON_ONCE(folio_order(folio) != PMD_ORDER)) > + return VM_FAULT_SIGBUS; > + > + if (arch_needs_pgtable_deposit()) { > + pgtable = pte_alloc_one(vma->vm_mm); > + if (!pgtable) > + return VM_FAULT_OOM; > + } This is interesting and nasty at the same time (only to make ppc64 boo3s with has tables happy). But it seems to be the right thing to do. > + > + ptl = pmd_lock(mm, vmf->pmd); > + if (pmd_none(*vmf->pmd)) { > + folio_get(folio); > + folio_add_file_rmap_pmd(folio, &folio->page, vma); > + add_mm_counter(mm, mm_counter_file(folio), HPAGE_PMD_NR); > + } > + insert_pfn_pmd(vma, addr, vmf->pmd, pfn_to_pfn_t(folio_pfn(folio)), > + vma->vm_page_prot, write, pgtable); > + spin_unlock(ptl); > + if (pgtable) > + pte_free(mm, pgtable); Ehm, are you unconditionally freeing the pgtable, even if consumed by insert_pfn_pmd() ? Note that setting pgtable to NULL in insert_pfn_pmd() when consumed will not be visible here. You'd have to pass a pointer to the ... pointer (&pgtable). ... unless I am missing something, staring at the diff. -- Cheers, David / dhildenb