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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66E45CAC582 for ; Fri, 12 Sep 2025 11:36:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C501F8E0013; Fri, 12 Sep 2025 07:36:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C27EB8E0005; Fri, 12 Sep 2025 07:36:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B3D908E0013; Fri, 12 Sep 2025 07:36:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A368A8E0005 for ; Fri, 12 Sep 2025 07:36:11 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 3EA9AC07BB for ; Fri, 12 Sep 2025 11:36:11 +0000 (UTC) X-FDA: 83880394542.15.AA5BB56 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf01.hostedemail.com (Postfix) with ESMTP id 8A1374000D for ; Fri, 12 Sep 2025 11:36:08 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XOj2mOFZ; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 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=1757676968; 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=L4WTNdMCGh54uRDM/L4Uxaq4pm+e6gS6JQHYqsqi25s=; b=wttq7EQvmWFm1K+7o4nYw00sXQjIb++HgY3KSDza8XbGIABBKX1cVtffoEeSaZvecvvlUv plEq/3QaIkNg5A+h3mknBzANQn2q+MqEs2DczvSXNZtCofWJkO0Yzjr6vK76S8xz6FCn7k e3YAj/mTY9aCiM76nBT9vO/AJnfgUPk= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XOj2mOFZ; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757676968; a=rsa-sha256; cv=none; b=HJNB3ucP3bFgLx61TwBkGT9Novyn2XhiHp04BitqMLp7A8kZa0kQjQ+x58TV8k6R4/1q7r ZtKaoqH8o0M4fRSi/C/oDkLRvYEKOMrEqjlDTKup0vnjCkUqrNcBVhzLBWwz6fSCGXVv3X Mc+YK0s5nP7926ugQg6VdHcL5ZVR+ZM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757676967; 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=L4WTNdMCGh54uRDM/L4Uxaq4pm+e6gS6JQHYqsqi25s=; b=XOj2mOFZ9fzs7SqurF0FUpLkugTTqOXC6JTSoQFXQKKtK2P3cqUH+hv52Zroggs8OUAMF8 ztYhs4ieaq5bdY+745oMRqnWwkNZlmEXVIWz2hQzf5OyEjAG8r+/wlgthu/hD6/qLMSqdS ZRCF/W7TqAdtY9be0lSkkE+4B2VSHFY= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-281-6rJqPVBUPTaxjr8xShhaOQ-1; Fri, 12 Sep 2025 07:36:06 -0400 X-MC-Unique: 6rJqPVBUPTaxjr8xShhaOQ-1 X-Mimecast-MFC-AGG-ID: 6rJqPVBUPTaxjr8xShhaOQ_1757676965 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-45de27bf706so8772275e9.0 for ; Fri, 12 Sep 2025 04:36:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757676965; x=1758281765; h=content-transfer-encoding:in-reply-to: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=L4WTNdMCGh54uRDM/L4Uxaq4pm+e6gS6JQHYqsqi25s=; b=Do54UYDXi69vERZaj0MB3wG05WCSwn/zm6djpKp+pT2q522rhNrciXTrZtAQqekUkn cZfRQqp1P6WApxA5LyFy0WCAsAI6ZgQip6RkrKvuxoF0blwGArcJozYpc/o6TTk9EWgi hi/5cFWnu2wHQEY6BgzTTgmfz39er4iHsry35FybmW7dTBffCfsKDIOBIqjjB+O5Nzxr PsD3AHVuAgSkYYl/33pR+8cdHGi1ZF/yttV76ueFaIs7ch0A3RmfVaJErIquhyJTdvpO GcZFaLAQBl6ATIEbXw684nr0AdFYJ3BDXJy7jHU4lS4lTEDCKp4yk9luWvcqAYW7i2C0 DmoQ== X-Forwarded-Encrypted: i=1; AJvYcCVkyPkK9mMtZ51ftSmA3Ji8yXp9i4/pwOzbRqXjYT+e1M6h/rYdyEo8u/nHxSCyykAOyDbUEamRsg==@kvack.org X-Gm-Message-State: AOJu0YxtOclWqlB9mY7mhuAG6EVXSuojLuxkKEQZfI4iGSfZKPXHLsKi GAKLdFt3XIMLKRF81kMkOZpwo8YsKUdw4w1SFUnOt0lRKwBNZc5MU1twG2masE5CraWKnXCZpzB 7QyhUsVoFrrqgVPrG4cCLBz28UUoC86JIUXdcfhSp6kvKc6DZc0EM X-Gm-Gg: ASbGnctA3+zMtNb1Fwwa5ks4ME2NZUpW6Hnrd7aX1xPcsqyDKYouhCn8kMP8NBDROB/ o3gEt5phMsHD4iwB70yBATEmmYgtW9Ygeg0lCeNB3X6XCMGvJ9b7IGoRIpEFT4sbyPBpUFhReGB 0m5M9JCbp3OmD5BfdHefklwf7wNxqwSZjyZKApiwsqIyxHuoGDNGG6sqrbJi3p2/Yyfnrc3QNVS anIt3yEvQ56JQpMm4u8+aVMGkiOSx4CLUtZsZZiaodpNkY5NOEkY033tvF7NxSSYAHDm62BFyL7 nlve5GafZHTeMw+Hs2saMBTvKflWLe2ggGvE6d8/K/mFvOPb+gy/peVueji1s8hNhxq60L4k6j/ HsorIbf4Hi+nahULpwcCGLi9Th54Iyus/gOqfnJ1e6k/JUQzWSjhS0txZnnbXUmh7fxY= X-Received: by 2002:a05:600c:4e4b:b0:45d:cff6:733f with SMTP id 5b1f17b1804b1-45f211d517emr27953585e9.11.1757676965172; Fri, 12 Sep 2025 04:36:05 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEApCot1i+5m775BUiDD6WRxTCaO0+qykFG5pVRf5Sw41hSYWcT5lrn+50Nw2D8nJepyAo5JA== X-Received: by 2002:a05:600c:4e4b:b0:45d:cff6:733f with SMTP id 5b1f17b1804b1-45f211d517emr27953335e9.11.1757676964784; Fri, 12 Sep 2025 04:36:04 -0700 (PDT) Received: from ?IPV6:2003:d8:2f20:da00:b70a:d502:3b51:1f2d? (p200300d82f20da00b70ad5023b511f2d.dip0.t-ipconnect.de. [2003:d8:2f20:da00:b70a:d502:3b51:1f2d]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3e760775842sm6503959f8f.7.2025.09.12.04.36.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Sep 2025 04:36:04 -0700 (PDT) Message-ID: <3f739d3e-f6fc-4a3f-9bbb-151a6dc6c083@redhat.com> Date: Fri, 12 Sep 2025 13:36:03 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: transhuge-stress: fix potential memory leak on realloc failure To: Haofeng Li <920484857@qq.com>, Andrew Morton Cc: 13266079573@163.com, lihaofeng@kylinos.cn, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com References: 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 1bV5IxS07F92IyQCvYotZ1FuATyaIFREhVyhEfmUv9Y_1757676965 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 8A1374000D X-Stat-Signature: zojysu4ic59zu3ea3ig1op673muthg9p X-HE-Tag: 1757676968-35699 X-HE-Meta: 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 hsr115SC 50x3bpBD6RGJE8oLJTLyziSQkMHTWVvBMrsbPSsvNNarWuWqB1iUamea05EFUiTZkQWDjAk6e/s8of6Om5+K2Qp79a5M6Rmrco1MgAybF18Uxeq/jRPjGpphzeB5laFwYgV2SWHIZWVwK3aNQKh02FZ052u6kgOHFVSmjJuvd9jyBmX0LQYB2FCLwrFfy0mNAoCdrOx5FE1QZg7RBWkgCdGpC6ccU4AF8T+4RG8diCUpAlybPWSSViUHhXIKvKeibPxb5TdiqiJ1jqmygmcpFbxdiCqmr3h5+IcK5PcYBPpcmdq5fK0TEPmidTf8RC/lRkZ2pJXpT3lw2OUoZBu7UMs6n+V6I7YwY9qrRgJ0kJceCL6JpeRq2H/woWthmTQbpnrttjGFRYI33hm1VCY1QVrUhR3Y5BXvYD3EF 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 12.09.25 12:10, Haofeng Li wrote: > From: David Hildenbrand >> What do you think happens when a process exits? :) > >> Correct! All memory ever allocated to that process gets freed, avoiding >> any memory leaks. > > Thanks for pointing this out. You are absolutely correct that the operating system will reclaim all allocated memory when a process exits, so there is no persistent memory leak in this specific scenario. > > I opted to add explicit memory freeing in the error path primarily as a practice for better long-term maintainability: > > It ensures correctness if the code structure changes in the future (e.g., becomes part of a longer-running routine). > > It maintains consistency with other error paths in the codebase. > > It prevents false positives from static analysis tools (like valgrind). > > I'm happy to adjust it if you still think it's preferable to remove the free() in this context. No code changes are required. This patch adds more complexity without any benefit. -- Cheers David / dhildenb