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 7F734C43458 for ; Thu, 9 Jul 2026 07:59:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6A3EF6B008A; Thu, 9 Jul 2026 03:59:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 67B0F6B0092; Thu, 9 Jul 2026 03:59:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 590A06B0093; Thu, 9 Jul 2026 03:59:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 390F66B008A for ; Thu, 9 Jul 2026 03:59:09 -0400 (EDT) Received: from smtpin27.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id C4D8E40465 for ; Thu, 9 Jul 2026 07:59:08 +0000 (UTC) X-FDA: 84968487576.27.62F51D2 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf24.hostedemail.com (Postfix) with ESMTP id 13DB1180004 for ; Thu, 9 Jul 2026 07:59:06 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=OUUATdfN; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf24.hostedemail.com: domain of vbabka@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=vbabka@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783583947; 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=oWwbm+zwEQ+hKtiYKEe/Fy+CBUoPDFgh3D2WLIb/mrw=; b=TRfnfm6KmLOBHUpk77d48RA3CFtG2xlvqtC28yxkx1WNyc4cqlPMFUWkYw6/8nMp14RMmm 3Jn8nZJneFD/p9ytfByjffB2Pj6jmGYNKwU5D0k8prVGF4E0a3CMHyRTQBot8ypX+VNCCP aiuhxGEAg4hOZ5p/cNDss9kJ/qvaNaI= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=OUUATdfN; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf24.hostedemail.com: domain of vbabka@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=vbabka@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783583947; b=xMGBK0frxIKQOp4uXzpGKmiSE/rUCcV/lsRg+vkaC397JnRdIJpFMryKLhDDeB8LWp7c0+ b0oKHJVLNNH9sJvM/tI5KL9nRYa1ST3N2KI3oKRnIwnHWhh7F2lP7ynqnEhL2yYQfkXbc8 8P0+tC3UFqFCXmbyuz9w4OzZTBNGG6E= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 6119E600C3; Thu, 9 Jul 2026 07:59:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 083FF1F000E9; Thu, 9 Jul 2026 07:59:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783583946; bh=oWwbm+zwEQ+hKtiYKEe/Fy+CBUoPDFgh3D2WLIb/mrw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=OUUATdfNZxV7YJWwlf5dZ9aP+RuPXbX1D1M4n3pTKC/QdSRi9kpL0Dfay2ab1/95T HZoYHz6ytOk0z4Ck27144zYmn+4ZOiazDR3h/rKXkrMsRYqcJ7LMDqwlBhkYYEEx1M KCLc/JcRLM2Q+ymVtGLbxEiWmuNoS2tiFrKXhRb2HWCW7hooTd5Y5pNN4BfY/7cpJz G0lu/XmZ5yvbghgKFMP4/JzL70GS4H0gG7sDVAIkezBekGYbjpj+ZqkCtMW1PlqLhF M+pHWuWyjXml6bEKtIEIxa4bokofQgmMVJWfZ41nbodkn0UEtPqVrlaj9AAoxFcRBm 7NInRHIeUd6wA== Message-ID: <706d312e-2509-459f-9339-3743d18f0ce5@kernel.org> Date: Thu, 9 Jul 2026 09:58:59 +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 , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , David Hildenbrand , 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: "Vlastimil Babka (SUSE)" Content-Language: en-US Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= 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-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 13DB1180004 X-Stat-Signature: d53jq5rn6mdq1g5o4goc3dist3g8ytow X-Rspam-User: X-HE-Tag: 1783583946-884716 X-HE-Meta: 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 U59y1/Ve kDsA8l6VS8ZwjaPxtPQi2lknt6WUKcK5z/1hlgoZL9touvtDYwl5Qrx4BD4e8vvG14CA3GpevnRKTjuXz6CweVphOLtsMf6NAcmKmO4SLKiEdEDqqpqMcMFH+WiqIGTdSWN8U2KC+K7/mEou0wh0EpIcWcwU60J+uOmbHQadFO4Yp/INPx7NYeHpqOUX3BBhA11iq8OmCBbnTgXIqaUrNuSVNE2b/yKNpKD/Z76UMBl+AwZnFPpcXOe9kr21z8EWXf9G5yUh/UaSKt2CarW3kXFT7mTPf1323l0R7oHQV5XqEerU1idy3TEX4kg== 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 Reviewed-by: Vlastimil Babka (SUSE) > --- > 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); > } > >