From patchwork Mon Sep 30 05:28:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13815373 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 5B74DCF6497 for ; Mon, 30 Sep 2024 05:28:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DAEA46B024D; Mon, 30 Sep 2024 01:28:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D5F536B024F; Mon, 30 Sep 2024 01:28:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFF2F6B0251; Mon, 30 Sep 2024 01:28:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id A1DC46B024D for ; Mon, 30 Sep 2024 01:28:40 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 4E0031A0DBC for ; Mon, 30 Sep 2024 05:28:40 +0000 (UTC) X-FDA: 82620274800.01.6D2185D Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf19.hostedemail.com (Postfix) with ESMTP id AD6061A0007 for ; Mon, 30 Sep 2024 05:28:37 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf19.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1727674098; a=rsa-sha256; cv=none; b=3nZKrbzAmYJpDFp81X3tJH2BMEKo98ZtdL64So2yEzJkvqri3Xj62cXW9QNw/sBTkFd0VC EAkhFJKDNZ0rq5yjjU16VUrWonoBNCFoGHoNBs5CTEHBQsXrzPtinPabdYNUn58HEmzUSl P30vgZn/gYW0tm3JoMT8g7+gtaUpiWQ= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf19.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1727674098; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qbGoAR1zwCLu/3w7sERyoSWkXQhkQEP4SBIOtWuk1/k=; b=wsKeKRgkIYF3FO1mjeDSvepFdB1tFkqMxvdhDuNaLy8N2grDClQv0juxhpyYIcOwMFPGZY KhkNcH0NUayxk/nGIbQoR6563gkM952S8awvTNLaCWjcqipQPIBEEiLUOkqSHYaOpJzpLI TQBxfEVnQJTSdqZbunSjjNv1E1/gJ64= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3ADDF1007; Sun, 29 Sep 2024 22:29:06 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BD6573F587; Sun, 29 Sep 2024 22:28:27 -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 v6 1/2] mm: Abstract THP allocation Date: Mon, 30 Sep 2024 10:58:11 +0530 Message-Id: <20240930052812.2627395-2-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240930052812.2627395-1-dev.jain@arm.com> References: <20240930052812.2627395-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspam-User: X-Stat-Signature: bs66pypkggezxip9k5bh534sn4xh8q7x X-Rspamd-Queue-Id: AD6061A0007 X-Rspamd-Server: rspam02 X-HE-Tag: 1727674117-170959 X-HE-Meta: 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 /yAGsth8 l4qO7+zbgVazdCP4PeXvT67sA17c2dBLEL4CSqt2BONg9WAWxnnI7jvNTOPh38AfJnw7DHW1hvSt5TAGkNfuV1rnYzWmfg9OWop/05c+Y+l5GScwExX8x000eucHt1Yf6zGCjmltm/9IzOBHgect1+QGOVpGICNnxH8X3SqHTGAgPU5PohaDR0JRh+KIwEUjgfqwZP+QbfwCpfoAmMdwIPEPDYtvHsKPK011E 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 4e34b7f89daf..e3bcdbc9baa2 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 Mon Sep 30 05:28:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dev Jain X-Patchwork-Id: 13815374 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 8BCAACF6497 for ; Mon, 30 Sep 2024 05:28:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0B6ED6B0259; Mon, 30 Sep 2024 01:28:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 067CB6B025A; Mon, 30 Sep 2024 01:28:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E232C6B025E; Mon, 30 Sep 2024 01:28:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C2B566B0259 for ; Mon, 30 Sep 2024 01:28:48 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 4F1968082E for ; Mon, 30 Sep 2024 05:28:48 +0000 (UTC) X-FDA: 82620275136.21.5556411 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf25.hostedemail.com (Postfix) with ESMTP id B57B1A0007 for ; Mon, 30 Sep 2024 05:28:46 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf25.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1727674024; a=rsa-sha256; cv=none; b=ZPveNJ8G9HeqGDmTZ+vSWke06FlrSFbGKG33VXikdT5ulTMiMSV/sc1QrlnYXNxlo12Y+y JQw/pymLVGHBbh9o3LerjemKm26ydLC2kKqw/P+1j9MomXScY7Ebo0RqzUvxuiojqU35in P65rkB2dGXhSNV3MZxFEBHRwQAiBRKo= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf25.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1727674024; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Quz7adx9iLY5xxA9l91IzYUjAhaQ3ljf3apGbfqa384=; b=EW6hh4He36iHFQTVsNbehWS2J8DoG7ugfHyHj1LRjZS6d4dvx7/lsVHEBjC3OVMgngttm5 vpqryMbAShWcVGcSBqDkwU2LwPV2dlkqskiKufofH3UIAcdULyUH+wEJlnXzYTyFRDDBO9 SzaQgmwbRn/bZgnVwrj8MABAvzPOV6M= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8A20AFEC; Sun, 29 Sep 2024 22:29:15 -0700 (PDT) Received: from e116581.blr.arm.com (e116581.arm.com [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 50F0F3F587; Sun, 29 Sep 2024 22:28:37 -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 v6 2/2] mm: Allocate THP on hugezeropage wp-fault Date: Mon, 30 Sep 2024 10:58:12 +0530 Message-Id: <20240930052812.2627395-3-dev.jain@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240930052812.2627395-1-dev.jain@arm.com> References: <20240930052812.2627395-1-dev.jain@arm.com> MIME-Version: 1.0 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: B57B1A0007 X-Stat-Signature: 3gapgpiqxcnc4ifoo1qzc4seu5qzno1e X-Rspam-User: X-HE-Tag: 1727674126-21133 X-HE-Meta: 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 VtrU3CCp YBraQBGf+kVEmjfVmIrrl8Hd3uuqLoaYrSM8BnAnusa7rKZEX/F9gV3weC1ua26gVMrtoRyKX/+LP7kUAXmLxYFA4y4SqwD/vRM9aKuOmSEOZjvM3Hza+xDUKFb27MNnHPy6OjEvnPxVvNhE65+o/NLJdgogBL9t/A+eYYQZjwPbiGef+JLv1NcLtZc1WqJ9vhtQhqGPxYbxXLGI= 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 e3bcdbc9baa2..4677ed76953c 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);