From patchwork Fri Dec 25 00:59:28 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 7920151 Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 5289B9F1AF for ; Fri, 25 Dec 2015 01:00:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 26BAD2037C for ; Fri, 25 Dec 2015 00:59:59 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC7D020373 for ; Fri, 25 Dec 2015 00:59:56 +0000 (UTC) Received: from ml01.vlan14.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id A2D0E1A242D; Thu, 24 Dec 2015 16:59:56 -0800 (PST) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by ml01.01.org (Postfix) with ESMTP id 912171A242D for ; Thu, 24 Dec 2015 16:59:55 -0800 (PST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP; 24 Dec 2015 16:59:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,476,1444719600"; d="scan'208";a="847979536" Received: from dwillia2-desk3.jf.intel.com ([10.54.39.136]) by orsmga001.jf.intel.com with ESMTP; 24 Dec 2015 16:59:55 -0800 Subject: [-mm PATCH v5 15/18] mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd From: Dan Williams To: akpm@linux-foundation.org Date: Thu, 24 Dec 2015 16:59:28 -0800 Message-ID: <20151225005623.19962.1972.stgit@dwillia2-desk3.jf.intel.com> In-Reply-To: <20151221054526.34542.25205.stgit@dwillia2-desk3.jf.intel.com> References: <20151221054526.34542.25205.stgit@dwillia2-desk3.jf.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Cc: Andrea Arcangeli , Dave Hansen , linux-nvdimm@lists.01.org, Peter Zijlstra , linux-mm@kvack.org, Mel Gorman , Sasha Levin , "Kirill A. Shutemov" X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A dax-huge-page mapping while it uses some thp helpers is ultimately not a transparent huge page. The distinction is especially important in the get_user_pages() path. pmd_devmap() is used to distinguish dax-pmds from pmd_huge() and pmd_trans_huge() which have slightly different semantics. Explicitly mark the pmd_trans_huge() helpers that dax needs by adding pmd_devmap() checks. Cc: Dave Hansen Cc: Mel Gorman Cc: Peter Zijlstra Cc: Andrea Arcangeli Cc: Andrew Morton Reported-by: Matthew Wilcox Reported-by: Kirill A. Shutemov Reported-by: Sasha Levin Signed-off-by: Dan Williams --- Changes since v4: 1/ Fold in a __split_huge_pmd() regression fix (Kirill) 2/ Add a missing pmd_devmap() check to pmd_trans_huge_lock() (Willy) arch/x86/include/asm/pgtable.h | 9 ++++++++- include/linux/huge_mm.h | 5 +++-- include/linux/mm.h | 7 +++++++ mm/huge_memory.c | 38 +++++++++++++++++++++----------------- mm/memory.c | 8 ++++---- mm/mprotect.c | 5 +++-- mm/pgtable-generic.c | 2 +- 7 files changed, 47 insertions(+), 27 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index dc962ae41597..993ce3c84ff4 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -167,13 +167,20 @@ static inline int pmd_large(pmd_t pte) #ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_trans_huge(pmd_t pmd) { - return pmd_val(pmd) & _PAGE_PSE; + return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; } static inline int has_transparent_hugepage(void) { return cpu_has_pse; } + +#ifdef __HAVE_ARCH_PTE_DEVMAP +static inline int pmd_devmap(pmd_t pmd) +{ + return !!(pmd_val(pmd) & _PAGE_DEVMAP); +} +#endif #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline pte_t pte_set_flags(pte_t pte, pteval_t set) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 8ca35a131904..d39fa60bd6bf 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -104,7 +104,8 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, #define split_huge_pmd(__vma, __pmd, __address) \ do { \ pmd_t *____pmd = (__pmd); \ - if (pmd_trans_huge(*____pmd)) \ + if (pmd_trans_huge(*____pmd) \ + || pmd_devmap(*____pmd)) \ __split_huge_pmd(__vma, __pmd, __address); \ } while (0) @@ -124,7 +125,7 @@ static inline bool pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, spinlock_t **ptl) { VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma); - if (pmd_trans_huge(*pmd)) + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) return __pmd_trans_huge_lock(pmd, vma, ptl); else return false; diff --git a/include/linux/mm.h b/include/linux/mm.h index 957afd1b10a5..96f396bbcc9f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1471,6 +1471,13 @@ static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address); #endif +#if !defined(__HAVE_ARCH_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE) +static inline int pmd_devmap(pmd_t pmd) +{ + return 0; +} +#endif + #if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU) static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 7356857d7356..4521bec67364 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1024,7 +1024,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, ret = -EAGAIN; pmd = *src_pmd; - if (unlikely(!pmd_trans_huge(pmd))) { + if (unlikely(!pmd_trans_huge(pmd) && !pmd_devmap(pmd))) { pte_free(dst_mm, pgtable); goto out_unlock; } @@ -1047,17 +1047,20 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, goto out_unlock; } - src_page = pmd_page(pmd); - VM_BUG_ON_PAGE(!PageHead(src_page), src_page); - get_page(src_page); - page_dup_rmap(src_page, true); - add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); + if (pmd_trans_huge(pmd)) { + /* thp accounting separate from pmd_devmap accounting */ + src_page = pmd_page(pmd); + VM_BUG_ON_PAGE(!PageHead(src_page), src_page); + get_page(src_page); + page_dup_rmap(src_page, true); + add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); + atomic_long_inc(&dst_mm->nr_ptes); + pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); + } pmdp_set_wrprotect(src_mm, addr, src_pmd); pmd = pmd_mkold(pmd_wrprotect(pmd)); - pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); set_pmd_at(dst_mm, addr, dst_pmd, pmd); - atomic_long_inc(&dst_mm->nr_ptes); ret = 0; out_unlock: @@ -1745,7 +1748,7 @@ bool __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, spinlock_t **ptl) { *ptl = pmd_lock(vma->vm_mm, pmd); - if (likely(pmd_trans_huge(*pmd))) + if (likely(pmd_trans_huge(*pmd) || pmd_devmap(*pmd))) return true; spin_unlock(*ptl); return false; @@ -2862,7 +2865,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, VM_BUG_ON(haddr & ~HPAGE_PMD_MASK); VM_BUG_ON_VMA(vma->vm_start > haddr, vma); VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PMD_SIZE, vma); - VM_BUG_ON(!pmd_trans_huge(*pmd)); + VM_BUG_ON(!pmd_trans_huge(*pmd) && !pmd_devmap(*pmd)); count_vm_event(THP_SPLIT_PMD); @@ -2975,14 +2978,15 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PMD_SIZE); ptl = pmd_lock(mm, pmd); - if (unlikely(!pmd_trans_huge(*pmd))) + if (pmd_trans_huge(*pmd)) { + page = pmd_page(*pmd); + if (PageMlocked(page)) + get_page(page); + else + page = NULL; + } else if (!pmd_devmap(*pmd)) goto out; - page = pmd_page(*pmd); __split_huge_pmd_locked(vma, pmd, haddr, false); - if (PageMlocked(page)) - get_page(page); - else - page = NULL; out: spin_unlock(ptl); mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PMD_SIZE); @@ -3012,7 +3016,7 @@ static void split_huge_pmd_address(struct vm_area_struct *vma, return; pmd = pmd_offset(pud, address); - if (!pmd_present(*pmd) || !pmd_trans_huge(*pmd)) + if (!pmd_present(*pmd) || (!pmd_trans_huge(*pmd) && !pmd_devmap(*pmd))) return; /* * Caller holds the mmap_sem write mode, so a huge pmd cannot diff --git a/mm/memory.c b/mm/memory.c index 9483d2b1dd3b..03b6fa406a28 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -950,7 +950,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src src_pmd = pmd_offset(src_pud, addr); do { next = pmd_addr_end(addr, end); - if (pmd_trans_huge(*src_pmd)) { + if (pmd_trans_huge(*src_pmd) || pmd_devmap(*src_pmd)) { int err; VM_BUG_ON(next-addr != HPAGE_PMD_SIZE); err = copy_huge_pmd(dst_mm, src_mm, @@ -1177,7 +1177,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); - if (pmd_trans_huge(*pmd)) { + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) { #ifdef CONFIG_DEBUG_VM if (!rwsem_is_locked(&tlb->mm->mmap_sem)) { @@ -3375,7 +3375,7 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, int ret; barrier(); - if (pmd_trans_huge(orig_pmd)) { + if (pmd_trans_huge(orig_pmd) || pmd_devmap(orig_pmd)) { unsigned int dirty = flags & FAULT_FLAG_WRITE; if (pmd_protnone(orig_pmd)) @@ -3404,7 +3404,7 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, unlikely(__pte_alloc(mm, vma, pmd, address))) return VM_FAULT_OOM; /* if an huge pmd materialized from under us just retry later */ - if (unlikely(pmd_trans_huge(*pmd))) + if (unlikely(pmd_trans_huge(*pmd) || pmd_devmap(*pmd))) return 0; /* * A regular pmd is established and it can't morph into a huge pmd diff --git a/mm/mprotect.c b/mm/mprotect.c index 9c1445dc8a4c..732e07baf76c 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -149,7 +149,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, unsigned long this_pages; next = pmd_addr_end(addr, end); - if (!pmd_trans_huge(*pmd) && pmd_none_or_clear_bad(pmd)) + if (!pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) + && pmd_none_or_clear_bad(pmd)) continue; /* invoke the mmu notifier if the pmd is populated */ @@ -158,7 +159,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, mmu_notifier_invalidate_range_start(mm, mni_start, end); } - if (pmd_trans_huge(*pmd)) { + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) split_huge_pmd(vma, pmd, addr); else { diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index c311a2ec6fea..9d4767698a1c 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -132,7 +132,7 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, { pmd_t pmd; VM_BUG_ON(address & ~HPAGE_PMD_MASK); - VM_BUG_ON(!pmd_trans_huge(*pmdp)); + VM_BUG_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); return pmd;