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 2BD50C43458 for ; Mon, 6 Jul 2026 08:37:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1F0156B00D5; Mon, 6 Jul 2026 04:37:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C7E86B00DA; Mon, 6 Jul 2026 04:37:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0DD796B00DB; Mon, 6 Jul 2026 04:37:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C5D066B00D5 for ; Mon, 6 Jul 2026 04:37:37 -0400 (EDT) Received: from smtpin15.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 4DE14C1B3D for ; Mon, 6 Jul 2026 08:37:37 +0000 (UTC) X-FDA: 84957698154.15.BC4039A Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf28.hostedemail.com (Postfix) with ESMTP id 8D95AC0004 for ; Mon, 6 Jul 2026 08:37:35 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=V7oHsUXz; spf=pass (imf28.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=1783327055; b=FaHTGGo8T0wsBf/lRXj24T8S/OffKpKuyfKQ1KfTmjengAphY21McJzXry1g1U+ds9nCtd Fe+71iadf4WVPps2DB9c0FGcW5g4ieuWo61wmpHKZyPRgpSpzohaF+TzUAr/uOrGJg+r4G clIY8+T9AW6yN9cqBlTE5g+mpKYg5q0= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=V7oHsUXz; spf=pass (imf28.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=1783327055; 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=AMcL1MBdVCvnx8Hy+bCvCz7qDrwotWXEZCOsItQUjCY=; b=D1tySLjAS1V7ERmJSynR/eGOq4X8LapPjVOgnD/wKyumySLc58DFCK1vQJqKW+dsfwsTd6 BIHWUOUaCdnLMTrw9baZ87eGLVRitx1gXL203Q4ZJl11rBKjFkq9d7RQpoKEpsUNNyCCws pu9WOp5c4+V5Mm2ez1PfOBpKnLjaZD8= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CC089418A0; Mon, 6 Jul 2026 08:37:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF02B1F000E9; Mon, 6 Jul 2026 08:37:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783327054; bh=AMcL1MBdVCvnx8Hy+bCvCz7qDrwotWXEZCOsItQUjCY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=V7oHsUXz6pTL/1uRlbjM1Tucw+X3ZMItcqFjPAprrw3l+fWPIv85z1yCWGv/NYAkC vHzlkqDcVCE6nkF5ivrb1Lzw30wNOkaF/PRUoKl7yACqxZBgc+SRefigFORNf/ZcZX y+E0Fwi0w4FeWbW/2T2MVWOZQAT2VBV4X77l6KZ1nCqPmY4wodnsn0Mr3UFLLPD0LW K8HgPTfNESZwta3mCtt2l4axckC0osYElf1u0s/BIaKKkPeTkMDs+0RL7TcNz9uYEQ B12BKfZykfuoFHCzNpO4++kw9g+HvHrW87s98SDLN2qaq72ymQpCA2dh7OJa2RUdGC 72DZ0tx95bDiA== Message-ID: <1bd9a8c7-aa7e-4784-99f9-ba2c5cdc3a68@kernel.org> Date: Mon, 6 Jul 2026 10:37:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/5] mm/percpu-km: clear page->private before free them To: Zi Yan , Andrew Morton , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Mike Rapoport , Dennis Zhou , Tejun Heo , Christoph Lameter , Alistair Popple Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260703-keep-subpage-private-zero-at-free-v2-0-2970fe777dd6@nvidia.com> <20260703-keep-subpage-private-zero-at-free-v2-1-2970fe777dd6@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: <20260703-keep-subpage-private-zero-at-free-v2-1-2970fe777dd6@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 8D95AC0004 X-Stat-Signature: 4hczeiw6eq34481bxugct93zxpi5hss6 X-HE-Tag: 1783327055-696968 X-HE-Meta: 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 zwSzl7qT ZR7bKrmbYTcwA+dALKF9yNMuwniOOpEhHnX9fsOCLZYkDXkELSqIWvzpALxRKrWL6eVjU8Im7M+9fQscmkVvG75mz+bStbr1C2f+K80YolgVcFRQI1InEMlOc/VYbehQbnBPKgAtH6AaIKizuU9cS170RyyUk8/aROH+qUFrlKdcZEDw7+73KLW0i8JtazJ6ViMeNVnvyU2B6HPgjzqJU3qlu8Utv1fFEliuILdKP0wXjWH48OfXX0aLDl50xUcqSyGsoNP/gA5Xsy65QHEx7lhWa8OkBineSM2R+IzJyYI2d4ILdcx6neUGtRw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/3/26 15:47, Zi Yan wrote: > page->private is cleared in free page path. In a subsequent commit, > tail_page->private will be checked and ensured to be zero. Clearing > percpu-km allocated pages' ->private to prevent triggering warnings later. > > Signed-off-by: Zi Yan > --- > mm/percpu-km.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/mm/percpu-km.c b/mm/percpu-km.c > index 4efa74a495cb6..7ffe84adadb9d 100644 > --- a/mm/percpu-km.c > +++ b/mm/percpu-km.c > @@ -94,8 +94,15 @@ static void pcpu_destroy_chunk(struct pcpu_chunk *chunk) > pcpu_stats_chunk_dealloc(); > trace_percpu_destroy_chunk(chunk->base_addr); > > - if (chunk->data) > + if (chunk->data) { > + struct page *pages = (struct page *)chunk->data; > + int i; > + > + /* clear chunk info from each page before free them */ > + for (i = 0; i < nr_pages; i++) > + pcpu_set_page_chunk(pages + i, NULL); > __free_pages(chunk->data, order_base_2(nr_pages)); > + } > pcpu_free_chunk(chunk); > } > > Un-doing what we did in pcpu_create_chunk. Acked-by: David Hildenbrand (Arm) -- Cheers, David