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 6069FC982DE for ; Mon, 21 Sep 2026 09:23:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 695886B00E9; Mon, 21 Sep 2026 05:23:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6743A6B00EA; Mon, 21 Sep 2026 05:23:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 583D76B00EA; Mon, 21 Sep 2026 05:23:00 -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 2F9326B00A6 for ; Mon, 21 Sep 2026 05:23:00 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 68469805D4 for ; Mon, 21 Sep 2026 09:22:59 +0000 (UTC) X-FDA: 85237230078.06.4E98B3E Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf08.hostedemail.com (Postfix) with ESMTP id 933F9160004 for ; Mon, 21 Sep 2026 09:22:57 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=kxB7xjuI; spf=pass (imf08.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789982577; 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=8CFoO3HjULZRPlh9ZYjAdBilyoIciysfYkAgUiyK+u4=; b=swLIWCWyTKQJ2hvOCksxkb0KQAbeP2GlhbkUL37FOLouyolo7e5GoHAArWngbGxJfd5+LV cMJOXuJDVG6GK1fFDUitRBsDIY1W/poGp9bZquWYO+00EF5fyrmOGPpKng2ZW0khx33kO8 sSgy4tbjWO0zqAReIXGQe2ELIFYpG0c= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=kxB7xjuI; spf=pass (imf08.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789982577; b=gz9ACytbkyTyZ7O8Ahv/hSXTzH2fHP7iOC2/jHO6Mq6bUUeR2bfwmHd0bG/4GJbKn9cZ3L 8sLNzeddrwOS1o5Fh5/d81F3p8hU50r8SDt0MF/jB+79myXxmdk5xUdaiL3hLZTRqDLCzY D/QBwlxJzPsgCCcBbw87OXsukiqruYc= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 4BF52403D1; Mon, 21 Sep 2026 09:22:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 848C71F00893; Mon, 21 Sep 2026 09:22:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789982576; bh=8CFoO3HjULZRPlh9ZYjAdBilyoIciysfYkAgUiyK+u4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kxB7xjuIgu9XSbE0bcEvnATOvW8Dks3rj4/Qaq6fXsLri3gZ1lho6AQisuaA1axMZ QDGJCV9LB2wRUOgqUO15KymsnUkll6IJ/E0fEpJyqMqE3PLeI+UTlLNHLiROzY6wUd mDasoKq9mSazdecv4u/T96AyYAHKmpGiBGA049UFWi2AMd8fto2neGDUAaEw3/kUIv QMxASG2IOCgua6Rf7ZlRW0IArUm0ezE5wA90wDjvbr5CXqsYEN8UypLvRlzCye4jFj +fBhxBJIrLOzbcU8Wn6QRo62L0t1iBMNTNjwtKvJcaatopydxAapuvBt6fou6CHMUK 09UBbdd5GGIsg== Message-ID: <6547c594-5669-4234-9ae4-ffac1ca74b69@kernel.org> Date: Mon, 21 Sep 2026 11:22:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 10/17] mm/page-flags: check page/folio->private instead of PG_private To: Zi Yan , "Matthew Wilcox (Oracle)" , Andrew Morton , Muchun Song , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Gregory Price , Ying Huang , Alistair Popple , Johannes Weiner , Qi Zheng , Shakeel Butt , Kairui Song Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Steven Rostedt , Masami Hiramatsu , Jan Kara , Mathieu Desnoyers , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Axel Rasmussen , Yuanchu Xie , Wei Xu , linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20260920-remove-pg_private-v5-0-bb68b6a21869@nvidia.com> <20260920-remove-pg_private-v5-10-bb68b6a21869@nvidia.com> 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: <20260920-remove-pg_private-v5-10-bb68b6a21869@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 933F9160004 X-Stat-Signature: zdjoct1rxkbrfwzyfz7eeqzn9amwdzc8 X-Rspam-User: X-HE-Tag: 1789982577-27666 X-HE-Meta: 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 bgyVeJPk QytS+p03v49hI5moQq1tYcOxApqE8lPFpzmkR+oBw/4W9Oyh1xUeI0Wuc6WMhFKkcmF3nO/8WaTnx6K0tSfi844FWGPjgMNH8TUuzH14Jb9UG2TUD8VdfG3UVXM899CIrj5c3Gy67BYEfDbE4KCAgFr7tFLPOThsXe8GRADc1nXEpgYQZPPOjIDNr7ff3XUyGpzemIodSIOmQt0yIGg2CDJF8L4P1XeA6bDn/O1sHC9D1ZxI+nRnACAibaAjOW2uuOjFRXDoRw+wt7V9pIDOodJn+Z+kdrne6XelQ823ymUfmzTlohgjsipbuDfx9LqCYoCZ1tT86KzXzwDrq2xTqpT9I7GqgCg3lUtsicoMW39+WwOSTYV33b3dea+d7mzmDsfNBHUxG6SDhFzRJ5K8CP7sP1g== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/21/26 04:28, Zi Yan wrote: > After the changes of the prior commits, page/folio->private != NULL is now > equivalent to checking PG_private. > > Stop checking PG_private on pages and folios and use page/folio->private > instead, except swapcache and hugetlb folios, because the former uses a > field (swp_entry_t swap) overlapping with ->private and the latter sets its > flags in ->private. Exclude swapcache and hugetlb when the code is meant to > check PG_private only. PG_swapcache and folio->swap.val cannot be set/clear > as a whole, so excluding swapcache with folio_test_swapcache() is not > reliable. Instead, use folio_test_swapbacked(), since PG_swapbacked is > stable when a folio is added to/removed from swapcache. Add a helper, > folio_has_attached_private(), for this check. > > folio_test_private() and PagePrivate() now read folio/page->private plainly > instead of an atomic read of PG_private bit, so KCSAN complains about > possible data races. Annotate them with data_race(). > > folio_expected_ref_count() can be called without the folio lock, so > annotate folio->mapping with data_race() while at it. > > folio_set/clear_private() and Set/ClearPagePrivate() become no-ops. > PG_private is no longer checked at page free time. They will be removed in > an upcoming commit. > > Remove KPF_PRIVATE since PG_private is no longer used. > Acked-by: David Hildenbrand (Arm) -- Cheers, David