From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x243.google.com (mail-pg0-x243.google.com [IPv6:2607:f8b0:400e:c05::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w2ZC81k0rzDq9K for ; Wed, 12 Apr 2017 03:43:00 +1000 (AEST) Received: by mail-pg0-x243.google.com with SMTP id 79so695060pgf.0 for ; Tue, 11 Apr 2017 10:43:00 -0700 (PDT) From: Oliver O'Halloran To: linuxppc-dev@lists.ozlabs.org Cc: arbab@linux.vnet.ibm.com, bsingharora@gmail.com, linux-nvdimm@lists.01.org, Oliver O'Halloran , "Aneesh Kumar K.V" , linux-mm@kvack.org Subject: [PATCH 2/9] mm/huge_memory: Deposit a pgtable for DAX PMD faults when required Date: Wed, 12 Apr 2017 03:42:26 +1000 Message-Id: <20170411174233.21902-3-oohall@gmail.com> In-Reply-To: <20170411174233.21902-1-oohall@gmail.com> References: <20170411174233.21902-1-oohall@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Although all architectures use a deposited page table for THP on anonymous VMAs some architectures (s390 and powerpc) require the deposited storage even for file backed VMAs due to quirks of their MMUs. This patch adds support for depositing a table in DAX PMD fault handling path for archs that require it. Other architectures should see no functional changes. Cc: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org Signed-off-by: Oliver O'Halloran --- mm/huge_memory.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index aa01dd47cc65..a84909cf20d3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -715,7 +715,8 @@ int do_huge_pmd_anonymous_page(struct vm_fault *vmf) } static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write) + pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write, + pgtable_t pgtable) { struct mm_struct *mm = vma->vm_mm; pmd_t entry; @@ -729,6 +730,12 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, entry = pmd_mkyoung(pmd_mkdirty(entry)); entry = maybe_pmd_mkwrite(entry, vma); } + + if (pgtable) { + pgtable_trans_huge_deposit(mm, pmd, pgtable); + atomic_long_inc(&mm->nr_ptes); + } + set_pmd_at(mm, addr, pmd, entry); update_mmu_cache_pmd(vma, addr, pmd); spin_unlock(ptl); @@ -738,6 +745,7 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, pfn_t pfn, bool write) { pgprot_t pgprot = vma->vm_page_prot; + pgtable_t pgtable = NULL; /* * If we had pmd_special, we could avoid all these restrictions, * but we need to be consistent with PTEs and architectures that @@ -752,9 +760,15 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, if (addr < vma->vm_start || addr >= vma->vm_end) return VM_FAULT_SIGBUS; + if (arch_needs_pgtable_deposit()) { + pgtable = pte_alloc_one(vma->vm_mm, addr); + if (!pgtable) + return VM_FAULT_OOM; + } + track_pfn_insert(vma, &pgprot, pfn); - insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write); + insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write, pgtable); return VM_FAULT_NOPAGE; } EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); @@ -1611,6 +1625,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, tlb->fullmm); tlb_remove_pmd_tlb_entry(tlb, pmd, addr); if (vma_is_dax(vma)) { + if (arch_needs_pgtable_deposit()) + zap_deposited_table(tlb->mm, pmd); spin_unlock(ptl); if (is_huge_zero_pmd(orig_pmd)) tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE); -- 2.9.3