From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6A60267F4C for ; Wed, 21 May 2025 12:06:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747829177; cv=none; b=VqL+5DbBAsdamsUGpufmmLeD5YGY94chtZz2cYJ70d/QFW0ne6sV/uNbi4Ep4ggpWAUidtYuiEqdIu8wNM+IUgPOgBKZrAWrlsdHKWhJKczMSxiC+UEM/xvMxmKxxxMT0K4mUPZUrhGOluTv52M4wqZEkCVIubJ0pJIhFEcgao0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747829177; c=relaxed/simple; bh=NuvhXzKwWVNNh3Mj8FQr+tvc8W2g+5K991fB2P5Y3aQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sY/iX0m0CD9gHf6K8dQO6pNv5tdcEiXBgIVg3bDt9Fx16pALi8ya+6C+KEYgyXsqqh7KK8eZg4mWYnx1yl80tMeDyz0Z9WekedajfuS7yL8dAdsLo8wOQGY2nRIEeCgXGVkIbOtiqGuJX62XnWP3NNGqW38KkenIb4wqKzdxzCQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aPOGpu4I; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aPOGpu4I" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747829174; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=01nQBgf3U3XQarvHKQKbgaSPFi0ZTBcwoE8UBRIN1oc=; b=aPOGpu4IQfrQb5bA9D1eGduB721+wsdxzy5j5xPrP8DI49qgCl/ICccEEDq50shiPKKK9I ScMg0FppZPiq0pSt5xG4agazmhznSNGcqnthdVeLtZT31MxPCduXYTorN4PgfFtKVVXlHc 3naAd9eZiz6ePooP+hASaQxCUvjtewk= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-665-6Z73jFbpNz-nLUH_P9E3uQ-1; Wed, 21 May 2025 08:06:12 -0400 X-MC-Unique: 6Z73jFbpNz-nLUH_P9E3uQ-1 X-Mimecast-MFC-AGG-ID: 6Z73jFbpNz-nLUH_P9E3uQ_1747829171 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-43d0830c3f7so49196435e9.2 for ; Wed, 21 May 2025 05:06:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747829171; x=1748433971; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=01nQBgf3U3XQarvHKQKbgaSPFi0ZTBcwoE8UBRIN1oc=; b=dHA6g9SzFoUFzcxpbsH7c04vNwxNUCLIFOU46Rj6E8nh1l4G+iGwolgQb1wRrhokyp LmwDor1uA9ewkUUxXCBiBKj++fzwTryUsX5pKb2+U/O7uPEEwBEhtkTM41Hyu8CtnmEj Un/3x8OFAdlIwZXA17Z4XKI2s5Dr1urC5OTCc0/ZJ+YtLWUPB07IKEfqQAKZ/E0Js8IK I3Wf9fpgvqzL7KgXEkyLjaZtGe9naGKrInDSKzLanCpIofqfakauib4rZX3MqBzOhYeo fiJhuvt6TvOfnM4s6b6R4Dohj0EyAFQ+wdyInCnRcM6QxXDQyirq4pY6fOw3giBUSpdY h3Pg== X-Forwarded-Encrypted: i=1; AJvYcCXdNj4NFtvhqAIisF0WOWNjInXECO01aZ6LVQW5mkYx0NPbX4mQ7fbX1SwT0/HxroL8rk+5EcNCfNsUWx8=@vger.kernel.org X-Gm-Message-State: AOJu0Yw9ADW8g0frODzd0dfW+6TECnG+TYesEX6Fk7AdpD1f1uruaxKB 553FSKha8nJKFNgryFTRvwrbJsY0cHoLiQKrOJz3bp4qoV5svnsEWMx3sREktgSz+VjwkB88MIF tuPBvuvQQRli0ozgTWq/5TjZ//wiDYOJfR62gEYwLiTU9aRXCZ/ZdFwddkKi5uFCpzA== X-Gm-Gg: ASbGncvMvD5bah/q+YHQVriTGW4i60LURWmuHo5TYxAo8wvGxKkRF3/wIfsfi3PBbrg 6ngfgGkMYjB+4gUZ6UUjJmhyOF4zLFGXL+LYQZJBfHVxMRuuTDVOam3Fq2xM1dKUkEv+zRw/buH 44sM9j3rQRnEYGgxw+S7V9BBQNOelj7mZIFlYrXLLjXWxiRG5zpUx+JHoznBEE6SqUt8jThFlIv v+PSmoWKYYKEnDl2bnrScF2HM5FQDDCZRa5pXiy9QSYXimITtQrsv/HpC1FDb9u+Nen92oNqhQ/ OO4VnKNGMQUPJ+NOUd5nqUNRT8fadZTy4eC1GT8blky9gVldWriqpHP6PeX2bYdNVgAxrBxMf8C 71JB7bjy97ogcn49UZM8a3FE70knyQl4W/Wx6Whs= X-Received: by 2002:a05:600c:154a:b0:43c:fcbc:9680 with SMTP id 5b1f17b1804b1-442fd664848mr153450835e9.25.1747829170875; Wed, 21 May 2025 05:06:10 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFlgtcVM/I7MVqWoMzPxbrhrrCqOaG89wRdWndpt86tHax21t0a+EFc7uXazYaQG0PsNikFYw== X-Received: by 2002:a05:600c:154a:b0:43c:fcbc:9680 with SMTP id 5b1f17b1804b1-442fd664848mr153450065e9.25.1747829170340; Wed, 21 May 2025 05:06:10 -0700 (PDT) Received: from ?IPV6:2003:d8:2f25:9c00:e2c7:6eb5:8a51:1c60? (p200300d82f259c00e2c76eb58a511c60.dip0.t-ipconnect.de. [2003:d8:2f25:9c00:e2c7:6eb5:8a51:1c60]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a35ca889e6sm19596701f8f.71.2025.05.21.05.06.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 May 2025 05:06:09 -0700 (PDT) Message-ID: <912757c0-8a75-4307-a0bd-8755f6135b5a@redhat.com> Date: Wed, 21 May 2025 14:06:08 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/5] mm: Optimize mprotect() by batch-skipping PTEs To: Dev Jain , akpm@linux-foundation.org Cc: ryan.roberts@arm.com, willy@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, anshuman.khandual@arm.com, peterx@redhat.com, joey.gouly@arm.com, ioworker0@gmail.com, baohua@kernel.org, kevin.brodsky@arm.com, quic_zhenhuah@quicinc.com, christophe.leroy@csgroup.eu, yangyicong@hisilicon.com, linux-arm-kernel@lists.infradead.org, hughd@google.com, yang@os.amperecomputing.com, ziy@nvidia.com References: <20250519074824.42909-1-dev.jain@arm.com> <20250519074824.42909-2-dev.jain@arm.com> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20250519074824.42909-2-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 19.05.25 09:48, Dev Jain wrote: Please highlight in the subject that this is only about MM_CP_PROT_NUMA handling. > In case of prot_numa, there are various cases in which we can skip to the > next iteration. Since the skip condition is based on the folio and not > the PTEs, we can skip a PTE batch. > > Signed-off-by: Dev Jain > --- > mm/mprotect.c | 36 +++++++++++++++++++++++++++++------- > 1 file changed, 29 insertions(+), 7 deletions(-) > > diff --git a/mm/mprotect.c b/mm/mprotect.c > index 88608d0dc2c2..1ee160ed0b14 100644 > --- a/mm/mprotect.c > +++ b/mm/mprotect.c > @@ -83,6 +83,18 @@ bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr, > return pte_dirty(pte); > } > > +static int mprotect_batch(struct folio *folio, unsigned long addr, pte_t *ptep, > + pte_t pte, int max_nr_ptes) > +{ > + const fpb_t flags = FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY; > + > + if (!folio_test_large(folio) || (max_nr_ptes == 1)) > + return 1; > + > + return folio_pte_batch(folio, addr, ptep, pte, max_nr_ptes, flags, > + NULL, NULL, NULL); > +} > + > static long change_pte_range(struct mmu_gather *tlb, > struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, > unsigned long end, pgprot_t newprot, unsigned long cp_flags) > @@ -94,6 +106,7 @@ static long change_pte_range(struct mmu_gather *tlb, > bool prot_numa = cp_flags & MM_CP_PROT_NUMA; > bool uffd_wp = cp_flags & MM_CP_UFFD_WP; > bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; > + int nr_ptes; > > tlb_change_page_size(tlb, PAGE_SIZE); > pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); > @@ -108,8 +121,10 @@ static long change_pte_range(struct mmu_gather *tlb, > flush_tlb_batched_pending(vma->vm_mm); > arch_enter_lazy_mmu_mode(); > do { > + nr_ptes = 1; > oldpte = ptep_get(pte); > if (pte_present(oldpte)) { > + int max_nr_ptes = (end - addr) >> PAGE_SHIFT; > pte_t ptent; > > /* > @@ -126,15 +141,18 @@ static long change_pte_range(struct mmu_gather *tlb, > continue; > > folio = vm_normal_folio(vma, addr, oldpte); > - if (!folio || folio_is_zone_device(folio) || > - folio_test_ksm(folio)) > + if (!folio) > continue; > > + if (folio_is_zone_device(folio) || > + folio_test_ksm(folio)) > + goto skip_batch; > + > /* Also skip shared copy-on-write pages */ > if (is_cow_mapping(vma->vm_flags) && > (folio_maybe_dma_pinned(folio) || > folio_maybe_mapped_shared(folio))) > - continue; > + goto skip_batch; > > /* > * While migration can move some dirty pages, > @@ -143,7 +161,7 @@ static long change_pte_range(struct mmu_gather *tlb, > */ > if (folio_is_file_lru(folio) && > folio_test_dirty(folio)) > - continue; > + goto skip_batch; > > /* > * Don't mess with PTEs if page is already on the node > @@ -151,7 +169,7 @@ static long change_pte_range(struct mmu_gather *tlb, > */ > nid = folio_nid(folio); > if (target_node == nid) > - continue; > + goto skip_batch; > toptier = node_is_toptier(nid); > > /* > @@ -159,8 +177,12 @@ static long change_pte_range(struct mmu_gather *tlb, > * balancing is disabled > */ > if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && > - toptier) > + toptier) { > +skip_batch: > + nr_ptes = mprotect_batch(folio, addr, pte, > + oldpte, max_nr_ptes); > continue; > + } I suggest a) not burying that skip_batch label in another if condition b) looking into factoring out prot_numa handling into a separate function first. Likely we want something like if (prot_numa) { nr_ptes = prot_numa_pte_range_skip_ptes(vma, addr, oldpte); if (nr_ptes) continue; } ... likely with a better function name, -- Cheers, David / dhildenb