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 62735C83029 for ; Mon, 30 Jun 2025 14:38:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 02CFA8D0003; Mon, 30 Jun 2025 10:38:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F1F698D0001; Mon, 30 Jun 2025 10:38:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE7798D0003; Mon, 30 Jun 2025 10:38:32 -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 CA2FB8D0001 for ; Mon, 30 Jun 2025 10:38:32 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 55999598A0 for ; Mon, 30 Jun 2025 14:38:32 +0000 (UTC) X-FDA: 83612322864.23.F05AAA0 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf10.hostedemail.com (Postfix) with ESMTP id E673EC000C for ; Mon, 30 Jun 2025 14:38:29 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=d6WMAHl8; spf=pass (imf10.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751294310; 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=dLNDWn+c6Slj1cTlasvqzpQ5+dIBruMnNq/SRSmpwEw=; b=PruZtlJIgIcq1rg98uzPZFITteWJlxTf/IR+wiVppVMI0PnFFjqYpwHzEYZHqZ27PQcTtB MqB2y7A6DaT/2iM9QQC/SAcAfHQ02ycwMRb/mN6epy+l56aXPfN6lpf4PywCojCIPDAob+ mSgY99r41gKjRVBqSXkO91XqKfNHs9c= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751294310; a=rsa-sha256; cv=none; b=vTK3WP9XkPi/cwtxV5a52jYtl/C0J6emwSirE5aY6REUu2AicJBQQRuwoYK+fC5UpqfcZj 3lsfKj02tNYh9lIDezYVzyyloI1sjfhzou4xUn9M4K7Kg45XxrJVkoTY80Jq+TdWRsxYYa U9EZB8nfl51Gg2znmB2vIeNRonh4PZ4= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=d6WMAHl8; spf=pass (imf10.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1751294309; 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=dLNDWn+c6Slj1cTlasvqzpQ5+dIBruMnNq/SRSmpwEw=; b=d6WMAHl85IvFDFdPi+upP32xpB2nZVfwbAPZU9nREAbwlibAyCAtoXzESARljbpa/lNesn 6oJur4psMhf2pxlE766fHvb5Q1KamTBUWlc5pZWOhnAhhja4CzxHaLdvl9teVRP1GpgZ42 A2aE0OS/8tbMIkledSzlu4hbHC7g2T8= 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-322-fWMRRY0bOayy93UZ2kX6BA-1; Mon, 30 Jun 2025 10:38:28 -0400 X-MC-Unique: fWMRRY0bOayy93UZ2kX6BA-1 X-Mimecast-MFC-AGG-ID: fWMRRY0bOayy93UZ2kX6BA_1751294307 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-451d5600a54so32055955e9.2 for ; Mon, 30 Jun 2025 07:38:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751294307; x=1751899107; 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=dLNDWn+c6Slj1cTlasvqzpQ5+dIBruMnNq/SRSmpwEw=; b=I7ODUyp9ib4m8uV5457WeuyGJ+xUi+QS394wp1HBWJF+vBQCmSULAuWZd9A4E5WIyQ gIWKfFaw0PL6Li7nKs+pCp6t8Tj0a1HJZKtnRmPYqRSPE/oTFEzblV+9nL6rjswe6vkm 1Gm3FmPkVQjvVfezsDx+sB24elWeIJb+kik7LGPswNO4RI7RXDn0l9C58bssMoWGs39a X3MH6TCG1nQnA4SDET+ta7Wi7Yq1O7cHTfrq2yRYXayF0l9ww6VI+afVDLS7LA2sy2sL J0YuzSjCGjxxi3S85+3INl0b7Z0wQGh/sGbba0yR7QQ/FByTWsavwogk33Nae+4g9tUY 2DEQ== X-Forwarded-Encrypted: i=1; AJvYcCWD9qYaeAh1Tx6CYVrBCGEaam1LfZhT/jtGOXE6FGs7frV7FuByLKEJIzfH+I5IyJgyZlLz0aVYqg==@kvack.org X-Gm-Message-State: AOJu0YxaehCAbWk4Sge0KQ8UkVcVLWqGYSERVNnq4HyuuQOO6f+jFzrG vgYy2kUIEUFYm0fT6JS9B73WPYrnDaMvl6/9tpNQ8wSTGsY782uoFqmg0cjtLgSbfE0mfxVYDpL Q1GKmm7Y5Q8ENEyi41foZuZFRjk6uJ/NEt1GAfkheumnN9WKzq89q X-Gm-Gg: ASbGncu/KqZVKG3SBm33fgQ/GDWlxPy8Tccxl/ziMMGe6VrWePXTYGMkBeu3zSszA1+ oiVNpBbGWz2ZoHBwlYQtRykHqFbH+iz9eu7TkDWPckaviGWYqprVk5xBOvONia2Q1AMlSKjFZwg zuUnVojVjKxZU0Zbyyy+DDXaPV832vhqXnIDlbrfXxY7WCIi9/MOXFSCT+OYwktVAqSKcn16od0 /i5A5Vd0NWx02nSgWnj6szuG1PT3vEigOkWck1DgRH7rMPQEJshs6ls+ZxR130p5sdxmcT90q3Z vUMx/3MP4SSwnKramunbr2vilQFjo1B1LYc/ANJYuKtD7SxkA84vVkocceQ/8uQPwi5ineqQ0Qo XewSjt273EYdntDTWaTIT2Mqay48xiss1hksBtdPSDxPezHyfmg== X-Received: by 2002:a05:600c:1c8b:b0:43c:fc04:6d35 with SMTP id 5b1f17b1804b1-453917ee4afmr129222665e9.4.1751294306669; Mon, 30 Jun 2025 07:38:26 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHnD9r4PvOzD5cwTLp6+K47C3mOJEJPn5vbMsxpz5jwCGLxU4Kqf3vYGoh2dZvH6exJkEnPWA== X-Received: by 2002:a05:600c:1c8b:b0:43c:fc04:6d35 with SMTP id 5b1f17b1804b1-453917ee4afmr129222315e9.4.1751294306269; Mon, 30 Jun 2025 07:38:26 -0700 (PDT) Received: from ?IPV6:2003:d8:2f40:b300:53f7:d260:aff4:7256? (p200300d82f40b30053f7d260aff47256.dip0.t-ipconnect.de. [2003:d8:2f40:b300:53f7:d260:aff4:7256]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3ac6ee0d0b9sm4870506f8f.18.2025.06.30.07.38.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 30 Jun 2025 07:38:25 -0700 (PDT) Message-ID: <1df06854-f5e6-493f-98e6-6426bd37da3c@redhat.com> Date: Mon, 30 Jun 2025 16:38:24 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/1] mm/debug_vm_pgtable: Use a swp_entry_t input value for swap tests To: Anshuman Khandual , Gerald Schaefer Cc: Andrew Morton , Matthew Wilcox , LKML , linux-mm , linux-s390@vger.kernel.org References: <20250623184321.927418-1-gerald.schaefer@linux.ibm.com> <20250623184321.927418-2-gerald.schaefer@linux.ibm.com> <9fb04185-5b71-46c0-b62c-0e0e6ee59e6e@arm.com> <20250625182846.5bce1aaf@thinkpad-T15> 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: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: ewHgQ1osr2FaISAyh3ZJcoMI_cyR4yQSvjJ8XpUCNGs_1751294307 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E673EC000C X-Stat-Signature: mqca4k9jox4zksnrxyp9pjzpkqt918bz X-HE-Tag: 1751294309-805304 X-HE-Meta: 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 IXNkZuUH 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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 30.06.25 06:18, Anshuman Khandual wrote: > > > On 25/06/25 10:17 PM, David Hildenbrand wrote: >>> [...] >>>>> @@ -1166,6 +1173,7 @@ static void __init init_fixed_pfns(struct pgtable_debug_args *args) >>>>>     static int __init init_args(struct pgtable_debug_args *args) >>>>>   { >>>>> +    unsigned long max_swap_offset; >>>>>       struct page *page = NULL; >>>>>       int ret = 0; >>>>>   @@ -1248,6 +1256,11 @@ static int __init init_args(struct pgtable_debug_args *args) >>>>>         init_fixed_pfns(args); >>>>>   +    /* See generic_max_swapfile_size(): probe the maximum offset */ >>>>> +    max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL)))); >>>> Why not directly use generic_max_swapfile_size() which is doing exact same thing. >>>> >>>> unsigned long generic_max_swapfile_size(void) >>>> { >>>>     return swp_offset(pte_to_swp_entry( >>>>             swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1; >>>> } >>> >>> Good question. I just moved this code here from pte_swap_exclusive_tests(), >>> see above, and did not think about that. Now I also wonder why >>> generic_max_swapfile_size() wasn't used before. >>> >>> But it is not exactly the same thing, there is an extra "+ 1" there. >>> Maybe that is the reason, but I don't really understand the details / >>> difference, and therefore would not want to change it. >>> >>> David, do you remember why you didn't use generic_max_swapfile_size() >>> in your pte_swap_exclusive_tests()? >> >> Excellent question. If only I would remember :) >> >> generic_max_swapfile_size() resides in mm/swapfile.c, which is only around with CONFIG_SWAP. >> >> It makes sense to have that function only if there are ... actual swapfiles. >> >> These checks here are independent of CONFIG_SWAP (at least in theory -- for migration entries etc we don't need CONFIG_SWAP), and we simply want to construct a swap PTE with all possible bits set. > > After this modification of PMD based swap test - there will be now > two uses for generic_max_swapfile_size(). Rather than refactoring > these into a similar helper in mm/debug_vm_pgtable.c - should the > existing helper just be moved outside of CONFIG_SWAP, thus making > it available in general ? As I said, having generic_max_swapfile_size() that returns something != 0 with !CONFIG_SWAP feels rather odd. No swap -> no swapfile -> no swapfile max size. No strong opinion though,, but desperately trying to de-duplicate 2 LOC might not be worth the churn at all. -- Cheers, David / dhildenb