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 65830C982E6 for ; Mon, 21 Sep 2026 21:05:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5997B6B00A4; Mon, 21 Sep 2026 17:05:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 523026B00A5; Mon, 21 Sep 2026 17:05:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3C36F6B00A6; Mon, 21 Sep 2026 17:05:33 -0400 (EDT) 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 0BCA46B00A4 for ; Mon, 21 Sep 2026 17:05:33 -0400 (EDT) Received: from smtpin22.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 1374280169 for ; Mon, 21 Sep 2026 21:05:32 +0000 (UTC) X-FDA: 85239000504.22.E73955A Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf03.hostedemail.com (Postfix) with ESMTP id 57B5E2000B for ; Mon, 21 Sep 2026 21:05:30 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ZZtvlp6Z; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ZZtvlp6Z; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790024730; b=tmVCSjCyiZeBMMCkBlGANBCY5WfP52vE7B2s2SFVSFM9cLqNj+bOhnQdcui0RcwP5tpB+o uMzkSoxDBC5fTzPH/a9qWv8U7T42ZAiFc8i8wJ3hL/rVYqUNhBppbbVja4dm7ML3QHZYXy Vdqo4Wz71Kc2zJkWRnXmpvLi4KmkORM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790024730; 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=/XBaHOvu3IMpuHFU5Xeyg5mt23hj1PsbznncaOl1HKQ=; b=1CSClMavw0fYDwB5r5FbTcXt2wmGkLzhtpCYWKU7+71eyjO543skPc5SIkdZAFNMITQplw FMcYsBrmRrC7yDTqWdTNbDIjzz3ilwB9svvJTpeNbq5JtOfM9MakapZkXT58MS+Z1E93Hg 1ibTxTFVDojolWguQn0DFCXDxcEQiec= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 71CBF60AA3; Mon, 21 Sep 2026 21:05:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A4111F008AB; Mon, 21 Sep 2026 21:05:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790024729; bh=/XBaHOvu3IMpuHFU5Xeyg5mt23hj1PsbznncaOl1HKQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZZtvlp6ZrSWFcUl1OOHGUcDffeC1oc11iWttO5FrOktb1gDYjwNvgpXSjGS2cseDd Yb+j7o88Fo2KxgNPdjxbYG+7pwgrGHVWltQUEIQGx6fWjtNO43wRm6cnaCoPROmq/n 0/vJx8fQYHGlNu533Rt+kWdWfr356YTeHRKQjE4XjZtpkIPVlZsQQXqf9Cc11vt30/ DLf6PTmNB1meZSKZm6eWcbAt60xg3vKFUni+8aEw8WLKLyDXo3Qlq2a6P7kybXEbjn c5ZSxaZhmofyksa+O4k6ulnXX5/iXC6VBU5THtM+bu239GLHqBkkybwHSvVFG8tq8i HSRhzhLyMpZXQ== Message-ID: Date: Mon, 21 Sep 2026 23:05:15 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 2/3] kselftest: mm: replace usage of /proc/self/smaps for check_huge_xxx() helper To: Yeoreum Yun Cc: Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260921-fix_split-v7-0-d25ec991159f@arm.com> <20260921-fix_split-v7-2-d25ec991159f@arm.com> <36465f31-59e2-43a5-8cd8-f8bb1844da3c@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 57B5E2000B X-Stat-Signature: wc3etgehop4hodzsg1hfcrprcwqkbjws X-Rspamd-Server: rspam01 X-HE-Tag: 1790024730-272166 X-HE-Meta: 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 sHscL5ae 4vKv8TQVO5rnWII7FhcB8WEWNKr6uOHu4tOYvwb+5Zm9mvs3Ha5m0E/x1Qp7tIHK1Ir1388GhjnMXsa6GTUVbucCvvsgWvsHulXcXYx7/pjeE3NHrMPOO/dHmMQWEf+nejcdRPJ1qK+lLsw6NgO6mi5Uzr34giju6uxtzRoXoGsQG21Qs/iKnjEAWGjtfm5sUWcAKgfVuIeLiExvlrUpDjmKo+cT+B+4PUau6q3SPtkCFD41fTLY1Fgcts5FoUutDagVMWdG2E0MQ6RVhnELdQ26MNs43k+DJXua+d3deB21s+Wtw9VvRMAd8iRFgRa4ErL848EdvvTow5wOI5hhkMtfUzOxWYzdAborb54soOkgGLXpofYPHw06ZCtZmwABJ4F8s Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/21/26 20:48, Yeoreum Yun wrote: > Hi, > >> On 9/21/26 12:40, Yeoreum Yun wrote: >>> Since glibc commit 321e1fc73f (“malloc: Enable 2MB THP by default on AArch64”), >>> glibc may call madvise(MADV_HUGEPAGE) for sufficiently large allocations >>> made by memalign(). >>> >>> The underlying VMA may start at a different address from the aligned >>> address returned by memalign(). Furthermore, a subsequent >>> madvise(MADV_HUGEPAGE) call does not split the VMA because the flag is >>> already set. >>> >>> This causes split_huge_page_test to fail because the check_huge_xxx() >>> helpers incorrectly require the address returned by memalign() to >>> match the VMA start address reported in /proc/self/smaps. >>> >>> Instead of relying on /proc/self/smaps, use /proc/self/pagemap and >>> /proc/kpageflags to detect huge-page mappings and large folios: >>> >>> 1. If hpage_size == pmd_pagesize, check PAGE_IS_HUGE instead of >>> using check_large_folios(), since only the mapping type matters. >>> This identifies PMD-mapped huge pages. >>> 2. Otherwise, use check_large_folios() to detect large folios. This >>> covers mTHP cases. >>> 3. Check the folio flags according to the type of huge page. >>> >>> Since shmem pages are also file-backed, simply check whether the page >>> is file-backed. >>> >>> Suggested-by: David Hildenbrand (Arm) >>> Suggested-by: Zi Yan >> >> Do we need a Fixes: tag? > > Since this change is required for the chaning of behavior of glibc, > I don't think we don't need to add Fixes tag in here? > Our test made wrong assumptions on the underlying behavior of the user space allocator (no VMA merging would happen). So I'd argue that we should add a Fixes: for the test. -- Cheers, David