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Mon, 16 Sep 2024 02:43:47 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, david@redhat.com, willy@infradead.org, kirill.shutemov@linux.intel.com Cc: ryan.roberts@arm.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, cl@gentwo.org, vbabka@suse.cz, mhocko@suse.com, apopple@nvidia.com, dave.hansen@linux.intel.com, will@kernel.org, baohua@kernel.org, jack@suse.cz, mark.rutland@arm.com, hughd@google.com, aneesh.kumar@kernel.org, yang@os.amperecomputing.com, peterx@redhat.com, ioworker0@gmail.com, jglisse@google.com, wangkefeng.wang@huawei.com, ziy@nvidia.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dev Jain Subject: [PATCH v4 1/2] mm: Abstract THP allocation Date: Mon, 16 Sep 2024 15:13:08 +0530 Message-Id: <20240916094309.1226908-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240916094309.1226908-1-dev.jain@arm.com> References: <20240916094309.1226908-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 184654000A X-Stat-Signature: rdiebgw8un1s63ahxt87oisyob9pwhz1 X-HE-Tag: 1726479836-167680 X-HE-Meta: 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 XHsi2WW7 xjBARLidKNFT3k3jyj8EB5P4KRruYkoQAo2NGwpgiqPB2bpJyFa49WymxxN1ypci6C5BM+cl3sjdJtfXkN9onrP2fKteNlfNcC1ZFmihHYXP9QoQFCv3v7Gq9oC1DMYlvn2XbDMSGTiZjoh/Y71rfmqLdYEQgndTOFV0yaaDcsL/iEaXqkh48aCET0J8iU7LDUQOODHCm7S+x7KE= 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: 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, except that, as David notes at [1], a PMD-aligned address should be passed to update_mmu_cache_pmd(). [1]: https://lore.kernel.org/all/ddd3fcd2-48b3-4170-bcaa-2fe66e093f43@redhat.com/ Signed-off-by: Dev Jain Acked-by: David Hildenbrand --- mm/huge_memory.c | 108 +++++++++++++++++++++++++++++------------------ 1 file changed, 66 insertions(+), 42 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2a73efea02d7..cdc632b8dc9c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1146,47 +1146,88 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, } EXPORT_SYMBOL_GPL(thp_get_unmapped_area); -static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, - struct page *page, gfp_t gfp) +static struct folio *vma_alloc_anon_folio_pmd(struct vm_area_struct *vma, + unsigned long addr) { - struct vm_area_struct *vma = vmf->vma; - struct folio *folio = page_folio(page); - pgtable_t pgtable; - unsigned long haddr = vmf->address & HPAGE_PMD_MASK; - vm_fault_t ret = 0; + unsigned long haddr = addr & HPAGE_PMD_MASK; + gfp_t gfp = vma_thp_gfp_mask(vma); + const int order = HPAGE_PMD_ORDER; + struct folio *folio = vma_alloc_folio(gfp, order, vma, haddr, true); - VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); + if (unlikely(!folio)) { + count_vm_event(THP_FAULT_FALLBACK); + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK); + goto out; + } + VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { folio_put(folio); count_vm_event(THP_FAULT_FALLBACK); count_vm_event(THP_FAULT_FALLBACK_CHARGE); - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK); - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); - return VM_FAULT_FALLBACK; + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK); + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); + return NULL; } folio_throttle_swaprate(folio, gfp); - pgtable = pte_alloc_one(vma->vm_mm); - if (unlikely(!pgtable)) { - ret = VM_FAULT_OOM; - goto release; - } - - folio_zero_user(folio, vmf->address); + folio_zero_user(folio, addr); /* * The memory barrier inside __folio_mark_uptodate makes sure that * folio_zero_user writes become visible before the set_pmd_at() * write. */ __folio_mark_uptodate(folio); +out: + return folio; +} + +static void __pmd_thp_fault_success_stats(struct vm_area_struct *vma) +{ + count_vm_event(THP_FAULT_ALLOC); + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC); + count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); +} + +static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd, + 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, pmd, entry); + update_mmu_cache_pmd(vma, haddr, pmd); + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); + __pmd_thp_fault_success_stats(vma); +} + +static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) +{ + unsigned long haddr = vmf->address & HPAGE_PMD_MASK; + struct vm_area_struct *vma = vmf->vma; + pgtable_t pgtable = NULL; + struct folio *folio; + vm_fault_t ret = 0; + + folio = vma_alloc_anon_folio_pmd(vma, vmf->address); + if (unlikely(!folio)) { + ret = VM_FAULT_FALLBACK; + goto release; + } + + pgtable = pte_alloc_one(vma->vm_mm); + if (unlikely(!pgtable)) { + ret = VM_FAULT_OOM; + goto release; + } vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); if (unlikely(!pmd_none(*vmf->pmd))) { goto unlock_release; } else { - pmd_t entry; - ret = check_stable_address_space(vma->vm_mm); if (ret) goto unlock_release; @@ -1200,21 +1241,11 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, VM_BUG_ON(ret & VM_FAULT_FALLBACK); return ret; } - - entry = mk_huge_pmd(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); pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); - set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); - update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); - add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); + map_anon_folio_pmd(folio, vmf->pmd, vma, haddr); mm_inc_nr_ptes(vma->vm_mm); deferred_split_folio(folio, false); spin_unlock(vmf->ptl); - count_vm_event(THP_FAULT_ALLOC); - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC); - count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); } return 0; @@ -1223,7 +1254,8 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, release: if (pgtable) pte_free(vma->vm_mm, pgtable); - folio_put(folio); + if (folio) + folio_put(folio); return ret; } @@ -1281,8 +1313,6 @@ static void set_huge_zero_folio(pgtable_t pgtable, struct mm_struct *mm, vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - gfp_t gfp; - struct folio *folio; unsigned long haddr = vmf->address & HPAGE_PMD_MASK; vm_fault_t ret; @@ -1333,14 +1363,8 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf) } return ret; } - gfp = vma_thp_gfp_mask(vma); - folio = vma_alloc_folio(gfp, HPAGE_PMD_ORDER, vma, haddr, true); - if (unlikely(!folio)) { - count_vm_event(THP_FAULT_FALLBACK); - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK); - return VM_FAULT_FALLBACK; - } - return __do_huge_pmd_anonymous_page(vmf, &folio->page, gfp); + + return __do_huge_pmd_anonymous_page(vmf); } static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, From patchwork Mon Sep 16 09:43:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13805222 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DD12C3ABA2 for ; Mon, 16 Sep 2024 09:44:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0AD446B008C; Mon, 16 Sep 2024 05:44:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 05D2E6B0092; 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Mon, 16 Sep 2024 02:44:34 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.42.11]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B4F903F66E; Mon, 16 Sep 2024 02:43:56 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, david@redhat.com, willy@infradead.org, kirill.shutemov@linux.intel.com Cc: ryan.roberts@arm.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, cl@gentwo.org, vbabka@suse.cz, mhocko@suse.com, apopple@nvidia.com, dave.hansen@linux.intel.com, will@kernel.org, baohua@kernel.org, jack@suse.cz, mark.rutland@arm.com, hughd@google.com, aneesh.kumar@kernel.org, yang@os.amperecomputing.com, peterx@redhat.com, ioworker0@gmail.com, jglisse@google.com, wangkefeng.wang@huawei.com, ziy@nvidia.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dev Jain Subject: [PATCH v4 2/2] mm: Allocate THP on hugezeropage wp-fault Date: Mon, 16 Sep 2024 15:13:09 +0530 Message-Id: <20240916094309.1226908-3-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240916094309.1226908-1-dev.jain@arm.com> References: <20240916094309.1226908-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: ECE5D180009 X-Stat-Signature: br7d6yp69anrydajd41uh7gw56pdx5oc X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1726479845-101941 X-HE-Meta: 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 pp0bEjKt hgnjiFrMzQ0LOlsKM2zolpsBEX8t18EmM2otIOBYQOdLczEt3ywqFdmOvy2oGwHQZ318+yPYGlQr1WUfEfHqaGLaX/zpghsZPEM26M0ebXGYQeqELo+vPYgPyX8cr0Z1DcdVFob5H+UlUtDySlQkPlk7ImA== 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: Introduce do_huge_zero_wp_pmd() to handle wp-fault on a hugezeropage and replace it with a PMD-mapped THP. Remember to flush TLB entry corresponding to the hugezeropage. In case of failure, fallback to splitting the PMD. Signed-off-by: Dev Jain --- mm/huge_memory.c | 44 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cdc632b8dc9c..eac7f58729b3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1796,6 +1796,41 @@ void huge_pmd_set_accessed(struct vm_fault *vmf) spin_unlock(vmf->ptl); } +static vm_fault_t do_huge_zero_wp_pmd(struct vm_fault *vmf) +{ + unsigned long haddr = vmf->address & HPAGE_PMD_MASK; + struct vm_area_struct *vma = vmf->vma; + struct mmu_notifier_range range; + struct folio *folio; + vm_fault_t ret = 0; + + folio = vma_alloc_anon_folio_pmd(vma, vmf->address); + if (unlikely(!folio)) { + ret = VM_FAULT_FALLBACK; + goto out; + } + + mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, haddr, + haddr + HPAGE_PMD_SIZE); + mmu_notifier_invalidate_range_start(&range); + vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); + if (unlikely(!pmd_same(pmdp_get(vmf->pmd), vmf->orig_pmd))) + goto release; + ret = check_stable_address_space(vma->vm_mm); + if (ret) + goto release; + (void)pmdp_huge_clear_flush(vma, haddr, vmf->pmd); + map_anon_folio_pmd(folio, vmf->pmd, vma, haddr); + goto unlock; +release: + folio_put(folio); +unlock: + spin_unlock(vmf->ptl); + mmu_notifier_invalidate_range_end(&range); +out: + return ret; +} + vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) { const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; @@ -1808,8 +1843,15 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd); VM_BUG_ON_VMA(!vma->anon_vma, vma); - if (is_huge_zero_pmd(orig_pmd)) + if (is_huge_zero_pmd(orig_pmd)) { + vm_fault_t ret = do_huge_zero_wp_pmd(vmf); + + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + + /* Fallback to splitting PMD if THP cannot be allocated */ goto fallback; + } spin_lock(vmf->ptl);