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Tue, 10 Sep 2024 23:56:20 -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 v3 1/2] mm: Abstract THP allocation Date: Wed, 11 Sep 2024 12:25:59 +0530 Message-Id: <20240911065600.1002644-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240911065600.1002644-1-dev.jain@arm.com> References: <20240911065600.1002644-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 59166C0008 X-Stat-Signature: 4y9n49n54m4jhe3ciunpfwkncd6jnqbh X-Rspam-User: X-HE-Tag: 1726037791-226813 X-HE-Meta: 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 WArIUhFZ YL7hGxNJonqovxqrXw3rcoRwo42e//07zxt8UoJzGI4PWYFy8pTStMtzrz7KzAAZTeioDJswgaYbz/yRl++SwtZQAKlCcrDXpu0bf1JSWl85a8zToPx0vAnel0s1AOfbHTj3CKxur56XEVNrJ7OJ64D+dag== 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. Signed-off-by: Dev Jain --- mm/huge_memory.c | 110 +++++++++++++++++++++++++++++------------------ 1 file changed, 67 insertions(+), 43 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 67c86a5d64a6..b96a1ff2bf40 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -943,47 +943,88 @@ 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 *pmd_thp_fault_alloc(gfp_t gfp, struct vm_area_struct *vma, + unsigned long haddr, 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; + 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); + goto out; } 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_pmd_thp(struct folio *folio, struct vm_fault *vmf, + 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, vmf->pmd, entry); + update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); + mm_inc_nr_ptes(vma->vm_mm); +} + +static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct folio *folio; + pgtable_t pgtable; + unsigned long haddr = vmf->address & HPAGE_PMD_MASK; + vm_fault_t ret = 0; + gfp_t gfp = vma_thp_gfp_mask(vma); + + folio = pmd_thp_fault_alloc(gfp, vma, haddr, 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; @@ -997,20 +1038,10 @@ 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); - mm_inc_nr_ptes(vma->vm_mm); + map_pmd_thp(folio, vmf, vma, haddr); 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); + __pmd_thp_fault_success_stats(vma); } return 0; @@ -1019,7 +1050,8 @@ 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; } @@ -1077,8 +1109,6 @@ 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; @@ -1129,14 +1159,8 @@ 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 Wed Sep 11 06:56:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13799768 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 4092FEE0213 for ; Wed, 11 Sep 2024 06:56:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CD349940010; Wed, 11 Sep 2024 02:56:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C5B6D94000B; Wed, 11 Sep 2024 02:56:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD3FC940010; 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Tue, 10 Sep 2024 23:56:30 -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 v3 2/2] mm: Allocate THP on hugezeropage wp-fault Date: Wed, 11 Sep 2024 12:26:00 +0530 Message-Id: <20240911065600.1002644-3-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240911065600.1002644-1-dev.jain@arm.com> References: <20240911065600.1002644-1-dev.jain@arm.com> MIME-Version: 1.0 X-Stat-Signature: e8t4utrfwfbutb17skkq8ipby5dgtfc4 X-Rspamd-Queue-Id: 74C9214000D X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1726037800-349086 X-HE-Meta: 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 tA97Gt+5 IG7AkLHeydJRkp8FYUTpeb7CoesM3+6RTCRFlBYDsFllnuu2xuUaHuEdtIFryIt71RKwM6P8B224dwVifEFZN3w18Ce8elF0ErfdilmG80h1tFsYXd6JJmPNlTso+isK+7I0jZqOEyjRSCoakeA65Wmanlw== 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. Change the helper introduced in the previous patch 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 | 52 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b96a1ff2bf40..3e28946a805f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -987,16 +987,20 @@ static void __pmd_thp_fault_success_stats(struct vm_area_struct *vma) static void map_pmd_thp(struct folio *folio, struct vm_fault *vmf, struct vm_area_struct *vma, unsigned long haddr) { - pmd_t entry; + pmd_t entry, old_pmd; + bool is_pmd_none = pmd_none(*vmf->pmd); 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); + if (!is_pmd_none) + old_pmd = pmdp_huge_clear_flush(vma, haddr, vmf->pmd); 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); - mm_inc_nr_ptes(vma->vm_mm); + if (is_pmd_none) + mm_inc_nr_ptes(vma->vm_mm); } static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) @@ -1576,6 +1580,41 @@ 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) +{ + struct vm_area_struct *vma = vmf->vma; + gfp_t gfp = vma_thp_gfp_mask(vma); + struct mmu_notifier_range range; + struct folio *folio; + vm_fault_t ret = 0; + + folio = pmd_thp_fault_alloc(gfp, vma, haddr, 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; + map_pmd_thp(folio, vmf, vma, haddr); + __pmd_thp_fault_success_stats(vma); + 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; @@ -1588,8 +1627,15 @@ 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, haddr); + + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + + /* Fallback to splitting PMD if THP cannot be allocated */ goto fallback; + } spin_lock(vmf->ptl);