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Mon, 7 Oct 2024 23:18:06 -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-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dev Jain Subject: [PATCH v7 1/2] mm: Abstract THP allocation Date: Tue, 8 Oct 2024 11:47:45 +0530 Message-Id: <20241008061746.285961-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241008061746.285961-1-dev.jain@arm.com> References: <20241008061746.285961-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 8B256120005 X-Stat-Signature: btyopm78tkfx98zxybi6hqsrs3mpwioz X-Rspam-User: X-HE-Tag: 1728368296-325991 X-HE-Meta: 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 BkqFTEf4 OgRvrhPNPzj/pxtKuWKI8M4GHIzE1F+EFYx6hL9HuaFXeaJSM932SPwBBdBvz47zG5e0oFVaDT3To30ftsBc3tbYa7IOHfrxHPsKWqteNo6w7WdjNPE7lspkj36F/gMxyJad7v4ET1avGPyJ+m31EC2L3ZnlE2wtry3o/fMkOfbspzAwImTmy9cu1QBEqfECTYq9Fzm88MnYs6anPcOF7t/80ZArgqPtSW87G 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/ Acked-by: David Hildenbrand Reviewed-by: Kefeng Wang Signed-off-by: Dev Jain --- mm/huge_memory.c | 98 ++++++++++++++++++++++++++++-------------------- 1 file changed, 57 insertions(+), 41 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3ca89e0279a7..e21c4f759e00 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1148,47 +1148,81 @@ 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; + gfp_t gfp = vma_thp_gfp_mask(vma); + const int order = HPAGE_PMD_ORDER; + struct folio *folio; - VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); + folio = vma_alloc_folio(gfp, order, vma, addr & HPAGE_PMD_MASK, true); + if (unlikely(!folio)) { + count_vm_event(THP_FAULT_FALLBACK); + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK); + return NULL; + } + + 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); + return folio; +} + +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); + 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 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; + struct folio *folio; + pgtable_t pgtable; + vm_fault_t ret = 0; + + folio = vma_alloc_anon_folio_pmd(vma, vmf->address); + if (unlikely(!folio)) + return VM_FAULT_FALLBACK; + + 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; @@ -1202,21 +1236,11 @@ 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; @@ -1283,8 +1307,6 @@ 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; @@ -1335,14 +1357,8 @@ 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 Tue Oct 8 06:17:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13825670 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 7E87BCED26E for ; Tue, 8 Oct 2024 06:18:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0DE176B0088; Tue, 8 Oct 2024 02:18:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 08EBB6B0089; Tue, 8 Oct 2024 02:18:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E99B06B008A; Tue, 8 Oct 2024 02:18:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id CE0786B0088 for ; 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Mon, 7 Oct 2024 23:18:16 -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-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dev Jain Subject: [PATCH v7 2/2] mm: Allocate THP on hugezeropage wp-fault Date: Tue, 8 Oct 2024 11:47:46 +0530 Message-Id: <20241008061746.285961-3-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241008061746.285961-1-dev.jain@arm.com> References: <20241008061746.285961-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: B0BB740004 X-Stat-Signature: fts6mcq6qzhjczg965kcsbnwmpygsdct X-HE-Tag: 1728368306-732780 X-HE-Meta: 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 g/e0wuFp cpZ3DCjx5cpOXa+2S8odfBs1z2DYVAx9RxsqdW0nBluLrseGCRb6h1+/yI574BI47g6DZF05bGp+Ugzg67MLLy9yILo6Y7XJ8cpfNFa9DgG0/NgmmfcBNTJFeySCYUYdvDdXizzucq/8vx29iURfgMQ4ANQYzQY/kN/QmTYeRvsz78Zkp7UwMJjZ2wBj+OEdRzIgUX0nKYzIzPyI= 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. Acked-by: David Hildenbrand Reviewed-by: Kefeng Wang Signed-off-by: Dev Jain --- mm/huge_memory.c | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e21c4f759e00..606ed782a15a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1790,6 +1790,38 @@ 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)) + return VM_FAULT_FALLBACK; + + 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); + return ret; +} + vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) { const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; @@ -1802,8 +1834,15 @@ 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);