From mboxrd@z Thu Jan 1 00:00:00 1970 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 8B87EC46CD2 for ; Tue, 30 Jan 2024 08:37:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 120A96B0099; Tue, 30 Jan 2024 03:37:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D1696B009D; Tue, 30 Jan 2024 03:37:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EB2C36B009F; Tue, 30 Jan 2024 03:37:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id D91C16B0099 for ; Tue, 30 Jan 2024 03:37:20 -0500 (EST) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 68FF1C06B6 for ; Tue, 30 Jan 2024 08:37:20 +0000 (UTC) X-FDA: 81735323040.12.D6597A5 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf05.hostedemail.com (Postfix) with ESMTP id 0A4AF10000F for ; Tue, 30 Jan 2024 08:37:17 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=BtwQkysi; spf=pass (imf05.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706603838; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=U45Fxm/MtG50A3gtC61QWpZLcXQoY54GjgFxR/yi5IE=; b=iH8x1oC+3B5Gc/qoIt2I9l31xoySuXjm644W1KPvE0gIizii8RPCGLSnyhjeW4o9mx+bh8 Taco8D0VmTSLvNQcFyxnSG6W1RbqNHGGUDQB5l5bmJ9OeXHowlZ53RDSBDye7INdGGGdN5 NddAt3bLXRtX5jb9hLe2EEQU9h95Xa4= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=BtwQkysi; spf=pass (imf05.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706603838; a=rsa-sha256; cv=none; b=OjkVrtrc7hZqudwYCz6+XYg99OVfmkDjArQ9H/os4AobTFQms8zj/3v81aFcPUiz6vIRT2 Jo6eGU2tFiEQmdjlh4/HwuUfU7FQbTOnrYzObWIZMSVyu1lsj+18+m4cC9f4S/rrvCnbxP FluuarMuzAYffh1vWn9X/HMYeFaIj3A= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706603837; 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=U45Fxm/MtG50A3gtC61QWpZLcXQoY54GjgFxR/yi5IE=; b=BtwQkysiV73coCUuVJmS2sut9C47L8Idk+Ks8CJsU8mgrhP4Ppmi1AzrhQvR5qLKC9jFrb mhNA4y8HlWBqCWvB+cThfucF1LRGN2/Jvp78ELr+ZESnDMTSNAu+EggSsnKHRgn9OERBZ5 qX6G+e9b7WoTzzBV3qM6+tqrmRT+WQM= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-691-0Sovm6clMSScn6Rr1ReohQ-1; Tue, 30 Jan 2024 03:37:16 -0500 X-MC-Unique: 0Sovm6clMSScn6Rr1ReohQ-1 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-40e530b7596so28770555e9.1 for ; Tue, 30 Jan 2024 00:37:15 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706603834; x=1707208634; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language: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=U45Fxm/MtG50A3gtC61QWpZLcXQoY54GjgFxR/yi5IE=; b=GjxRnIf0ltFvrLp6UykmBKtwy75K1zQVq1SixNMMJzrefTjhaYV9eHQa74vKEZRv3Y hWuIaQyCGo5ZJnF11ITkxXC2cN+5ZupcEzteJNdNNrIR70EINLjSSPemjEVWOqrPaXCP MvcFKwVXvSK+NjparApYMUdmrz9A/gZ8knLKAoyOUzCKYX2GsZzV3AGeGAqa53aJC59y Yzff54AoTt8Elp1Bx9aYb3Cvpu7asutQXfqKT742cw2FVHDDKvBhIuS17Isc2Te2/x0F m5arvbNTgi/sJWh9iQ4C2UWAWq1ZoobaFMc/j8LqSTZ7xZA6k25ZprD23kl2aGST0bSJ N+gw== X-Gm-Message-State: AOJu0Yw/1oj5/aM0ImjJFIXTPzkWkUg88xu6kKympkj8EZWlgr8Vdmt3 Gw+x6fQShcUuuzJ/NQs2SC0XCec0qMD8nsOhfAMSzmuNLP9RN14YRY+wKeNdu/MlYfPnNGkK4te ecCSmr94wfVoXaCgytghCsKdtFY8UgznRWQMGBImKkCrcO5DL X-Received: by 2002:a05:600c:190f:b0:40e:b93e:4a0f with SMTP id j15-20020a05600c190f00b0040eb93e4a0fmr7482832wmq.19.1706603834530; Tue, 30 Jan 2024 00:37:14 -0800 (PST) X-Google-Smtp-Source: AGHT+IFwkrtXtDO2gDcswLvVnF7XXvZ9DZQ0hnWmecx9yh3ExpmlwLhlL6D50z4cHWyxah3UEzsYlQ== X-Received: by 2002:a05:600c:190f:b0:40e:b93e:4a0f with SMTP id j15-20020a05600c190f00b0040eb93e4a0fmr7482804wmq.19.1706603834118; Tue, 30 Jan 2024 00:37:14 -0800 (PST) Received: from ?IPV6:2003:cb:c708:2700:bdf6:739b:9f9d:862f? (p200300cbc7082700bdf6739b9f9d862f.dip0.t-ipconnect.de. [2003:cb:c708:2700:bdf6:739b:9f9d:862f]) by smtp.gmail.com with ESMTPSA id h9-20020a05600c350900b0040fa661ee82sm262267wmq.44.2024.01.30.00.37.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Jan 2024 00:37:13 -0800 (PST) Message-ID: Date: Tue, 30 Jan 2024 09:37:12 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 3/9] mm/memory: further separate anon and pagecache folio handling in zap_present_pte() To: Ryan Roberts , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andrew Morton , Matthew Wilcox , Catalin Marinas , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Michael Ellerman , Christophe Leroy , "Naveen N. Rao" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org References: <20240129143221.263763-1-david@redhat.com> <20240129143221.263763-4-david@redhat.com> <40cfb242-ceb0-44c6-afe7-c1744825dc62@arm.com> From: David Hildenbrand 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: <40cfb242-ceb0-44c6-afe7-c1744825dc62@arm.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 0A4AF10000F X-Rspam-User: X-Stat-Signature: mrzwb4my1trg7bwhzepf6567xwbjxu7b X-Rspamd-Server: rspam01 X-HE-Tag: 1706603837-803079 X-HE-Meta: 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 vTWVc7XK 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 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: On 30.01.24 09:31, Ryan Roberts wrote: > On 29/01/2024 14:32, David Hildenbrand wrote: >> We don't need up-to-date accessed-dirty information for anon folios and can >> simply work with the ptent we already have. Also, we know the RSS counter >> we want to update. >> >> We can safely move arch_check_zapped_pte() + tlb_remove_tlb_entry() + >> zap_install_uffd_wp_if_needed() after updating the folio and RSS. >> >> While at it, only call zap_install_uffd_wp_if_needed() if there is even >> any chance that pte_install_uffd_wp_if_needed() would do *something*. >> That is, just don't bother if uffd-wp does not apply. >> >> Signed-off-by: David Hildenbrand >> --- >> mm/memory.c | 16 +++++++++++----- >> 1 file changed, 11 insertions(+), 5 deletions(-) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index 69502cdc0a7d..20bc13ab8db2 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -1552,12 +1552,9 @@ static inline void zap_present_pte(struct mmu_gather *tlb, >> folio = page_folio(page); >> if (unlikely(!should_zap_folio(details, folio))) >> return; >> - ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); >> - arch_check_zapped_pte(vma, ptent); >> - tlb_remove_tlb_entry(tlb, pte, addr); >> - zap_install_uffd_wp_if_needed(vma, addr, pte, details, ptent); >> >> if (!folio_test_anon(folio)) { >> + ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); >> if (pte_dirty(ptent)) { >> folio_mark_dirty(folio); >> if (tlb_delay_rmap(tlb)) { >> @@ -1567,8 +1564,17 @@ static inline void zap_present_pte(struct mmu_gather *tlb, >> } >> if (pte_young(ptent) && likely(vma_has_recency(vma))) >> folio_mark_accessed(folio); >> + rss[mm_counter(folio)]--; >> + } else { >> + /* We don't need up-to-date accessed/dirty bits. */ >> + ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); >> + rss[MM_ANONPAGES]--; >> } >> - rss[mm_counter(folio)]--; >> + arch_check_zapped_pte(vma, ptent); > > Isn't the x86 (only) implementation of this relying on the dirty bit? So doesn't > that imply you still need get_and_clear for anon? (And in hindsight I think that > logic would apply to the previous patch too?) x86 uses the encoding !writable && dirty to indicate special shadow stacks. That is, the hw dirty bit is set by software (to create that combination), not by hardware. So you don't have to sync against any hw changes of the hw dirty bit. What you had in the original PTE you read is sufficient. -- Cheers, David / dhildenb