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 05247C27C75 for ; Fri, 14 Jun 2024 07:36:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DF5F26B010E; Fri, 14 Jun 2024 03:34:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D97946B0110; Fri, 14 Jun 2024 03:34:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BEAA26B010E; Fri, 14 Jun 2024 03:34:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id C3C3A6B0112 for ; Fri, 14 Jun 2024 03:32:08 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 6213B12050C for ; Fri, 14 Jun 2024 07:32:08 +0000 (UTC) X-FDA: 82228675536.07.74B17A2 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf01.hostedemail.com (Postfix) with ESMTP id 187704000A for ; Fri, 14 Jun 2024 07:32:05 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LZJGG54A; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 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=1718350324; a=rsa-sha256; cv=none; b=kNx8mGDG8FPBEI31Uw0BGuCT36gqagY39DMhPv/ZSYAayqqsADYvAHlitGUy7daAyJvG/n XmwwVTcYucxoiRJm6f3ppIVWKVMk/HDqspBSREq2eCrJtpMuBH4PEgQ40/uK9Ts2M1/Oc5 xdcjPV4qNbgAC11SYKc++CpMTyCv2EM= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LZJGG54A; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 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=1718350324; 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=JQQxsPBCGNlGltg90dHlzYb1+dKHXWo1jn5ufOqQtzw=; b=UR7WmhY5R9K+rKdFp7hLROSEnYwf8w1OABCYx7+nGFC/HoIT51xXLhlz350QaFYxtpxzFT waUOqWDgSKfAyOd74CabsH3ITxNMCleEZXjSjbF4DZ16OlRKFkcVoI0Wy1Uhoq88fK5mYm WgJJPSHsPdXx9EtJP/eXlj5lpAJ0BBI= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718350325; 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=JQQxsPBCGNlGltg90dHlzYb1+dKHXWo1jn5ufOqQtzw=; b=LZJGG54AJSGhzaEh/4TuJCCHM2aguKyFCA0w09A7iz/6vpcSfyUnMEpHHivLxXbnoOv08e jheojfeJOHzhnYeUZy33yBlWTr0tfCRhDsN1BfEk4MSo3a6hiCcyGMSa2LK0WZpBWIZZaj YyJ3vEao37cn3XsMhw8+agCCUJbm/5Q= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-444-WX5Z0w-BMkKh9EFdQ6DLxQ-1; Fri, 14 Jun 2024 03:32:03 -0400 X-MC-Unique: WX5Z0w-BMkKh9EFdQ6DLxQ-1 Received: by mail-lf1-f69.google.com with SMTP id 2adb3069b0e04-52b998cb52eso1307280e87.3 for ; Fri, 14 Jun 2024 00:32:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718350322; x=1718955122; 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=JQQxsPBCGNlGltg90dHlzYb1+dKHXWo1jn5ufOqQtzw=; b=gU2Ae/ZI0dzq7LbcGbni3IUefyAF073775YC2w+JNPyPRtbXqjHDdSS0ntVZ5EbUOj DP57v2YxSEhGmzJeOODdO5hQcGaHzUIuIUubmQ3Ymoz4G5+k5aheMN31s109psZ9F3dz urxP3YceIigOdN3hYf3VgQ6lnkeSxAiXlOOtSlwyqRmnWAL8/jXNKvZGdfItid9bOOwY C4G+QgizSJlg1q5BCH1V97cNa6uojXtaUl/0pdAym7CQ8l/X3tv1gIAfvADomLjMowxQ ClgmZbqn0a9HxARdy6BReHm2eNR7TtqS51m+CnAifVM6JG7VkNzNdU2XOKMuXkwmv1Vg NuBg== X-Forwarded-Encrypted: i=1; AJvYcCVj6XHrIClmhUNBvafwbtOkLowO0s0ZNhM0vTGMRnSwPfCzghfxqvd1Pbk9/1bq9kCRQNlUWRk24ZeJm78hD4Gu2bk= X-Gm-Message-State: AOJu0Yw1cIcflC3UTgf8BzzJYtcGPUeEbYKOQVxiqZPPcgK6YBR9938v N/q/+KsxyJo+O/PD0YjDkGFH14pA8d/5mFBwYSvrZGLhPZKTLD7ik+oKQTLpzJU5zOWlzId/LLi v7tJbWVT2azmwntl6UUZk7GnYoyIleH0P8oWfs+NqpChdrISF X-Received: by 2002:a05:6512:24c:b0:52c:84a5:6617 with SMTP id 2adb3069b0e04-52ca6e9eb89mr1073953e87.68.1718350322138; Fri, 14 Jun 2024 00:32:02 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFihBuTEOEDGNiwwCtY19FqpqtczDOedWWjPsEX1AockcBtJRBs033ICPEr5aYYYymQLaAzQg== X-Received: by 2002:a05:6512:24c:b0:52c:84a5:6617 with SMTP id 2adb3069b0e04-52ca6e9eb89mr1073926e87.68.1718350321633; Fri, 14 Jun 2024 00:32:01 -0700 (PDT) Received: from ?IPV6:2003:d8:2f4f:2b00:69b5:3684:56c:6dd5? (p200300d82f4f2b0069b53684056c6dd5.dip0.t-ipconnect.de. [2003:d8:2f4f:2b00:69b5:3684:56c:6dd5]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-360750ad082sm3504522f8f.59.2024.06.14.00.32.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 14 Jun 2024 00:32:01 -0700 (PDT) Message-ID: Date: Fri, 14 Jun 2024 09:31:59 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] um/mm: get max_low_pfn from memblock To: Wei Yang , richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, linux-mm@kvack.org, Jason Lunz , Jeff Dike , Paolo 'Blaisorblade' Giarrusso , Alasdair G Kergon , Jens Axboe , Andrew Morton , Mike Rapoport , Tiezhu Yang References: <20240614015840.12632-1-richard.weiyang@gmail.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: <20240614015840.12632-1-richard.weiyang@gmail.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-Stat-Signature: onc7gun1occxw4d5kn6dtuimp6wnbxt7 X-Rspamd-Queue-Id: 187704000A X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1718350325-805542 X-HE-Meta: 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 Ag+6qeEp 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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 14.06.24 03:58, Wei Yang wrote: > Current calculation of max_low_pfn is introduced in commit af84eab20891 > ("[PATCH] uml: fix LVM crash"). It is intended to set max_low_pfn to the > same value as max_pfn. > > But I am not sure why the max_pfn is set to totalram_pages, which > represents the number of usable pages in system instead of an absolute > page frame number. (The change history stops there.) > > While we can get the maximum page frame number from memblock, this looks > more reasonable than setting to totalram_pages. > > Also this would help changing totalram_pages accounting, since we plan > to move the accounting into __free_pages_core(). With this change, > totalram_pages may not represent the total usable pages at this point, > since some pages would be deferred initialized. Question is if deferred page init is even a thing on UM. But it certainly looks odd+suspiciously wrong to rely on totalram_pages(). > > Signed-off-by: Wei Yang > CC: Jason Lunz > CC: Jeff Dike > Cc: Paolo 'Blaisorblade' Giarrusso > Cc: Alasdair G Kergon > Cc: Jens Axboe > CC: Andrew Morton > CC: Mike Rapoport (IBM) > CC: David Hildenbrand > > --- > A simple UML bootup test looks good. > --- > arch/um/kernel/mem.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c > index ca91accd64fc..ca682879e28f 100644 > --- a/arch/um/kernel/mem.c > +++ b/arch/um/kernel/mem.c > @@ -73,7 +73,7 @@ void __init mem_init(void) > > /* this will put all low memory onto the freelists */ > memblock_free_all(); > - max_low_pfn = totalram_pages(); > + max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); > max_pfn = max_low_pfn; > kmalloc_ok = 1; > } Matches what a bunch of other archs do. Acked-by: David Hildenbrand Randomly staring at other users: arch/loongarch/kernel/numa.c: max_low_pfn = PHYS_PFN(memblock_end_of_DRAM()); arch/loongarch/kernel/setup.c: max_low_pfn = PFN_PHYS(memblock_end_of_DRAM()); What? the latter cannot possibly be right, no? Looks odd at least. Only applies to CONFIG_OF_EARLY_FLATTREE. CCing loongarch maintainer. -- Cheers, David / dhildenb