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 7F85BC43602 for ; Fri, 3 Jul 2026 14:52:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 710DE6B00DE; Fri, 3 Jul 2026 10:52:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6E8CD6B00E2; Fri, 3 Jul 2026 10:52:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 600C96B00E3; Fri, 3 Jul 2026 10:52:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 3ACB26B00DE for ; Fri, 3 Jul 2026 10:52:57 -0400 (EDT) Received: from smtpin12.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id B426912018D for ; Fri, 3 Jul 2026 14:52:56 +0000 (UTC) X-FDA: 84947757552.12.E659319 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) by imf23.hostedemail.com (Postfix) with ESMTP id 88F6D140003 for ; Fri, 3 Jul 2026 14:52:54 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=mydS1cG0; spf=pass (imf23.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.171 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783090375; b=CHiH8PRbfh6MITLayisgXYlVNmD2IN6EzcmJpbVYkKb+Wh1A1k6MtbTY3GXvVQjhbs3vZ0 dAYA2uIzgRZhQH2Y0PNzFSWUS9DP1gwLUmOFwlXbiq7/Sz8BJAfha4OA4VoQhhkNIItDw4 eWev8GgAIW/Q8AuPj9xwFzRcTIvgUno= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783090375; 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=78pFcvGqBsTyEx7R+SOnLGnzaGBXiO97ypFlieLOwVk=; b=blNJkqtou5YgLZAYQLZtD+COgELRbcyhufN4NUnA9I1dAJwLcNcRWRHkmP0yyZLa+4x2ik GwsZXfnnQYqjOBCDaWWufmo5A1Q77wVeKA4tzbmjoY6VwjKfig8fJaKVakIHNgqngFbpx5 hvOM4fV547iNpnm6nPGnyl0IcxV3g6A= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=mydS1cG0; spf=pass (imf23.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.171 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Message-ID: <1f9e4322-1c5e-4409-9a12-ead280bfa4bd@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783090372; 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; bh=78pFcvGqBsTyEx7R+SOnLGnzaGBXiO97ypFlieLOwVk=; b=mydS1cG0VikRlAPagxdsHIFdCh2aej7rbmihV5PMR9Pk5I2mabCesa9j97GUksl0CxTJUi YLw6g7RU+UGOpukqE4gmXAQqPTOHWHg/+HnMaM3rN+i3Z8AY5nchHjk+iAqyLc+sFE3TCQ sEDbRSpgdlHolEzoreltzIkrO2bKZ2A= Date: Fri, 3 Jul 2026 22:52:32 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v2 5/5] mm/page_alloc: remove set_page_private() in prep_compound_tail() Content-Language: en-US To: Zi Yan Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Barry Song , David Hildenbrand , Michal Hocko , Andrew Morton , "Liam R. Howlett" , Dennis Zhou , Christoph Lameter , Mike Rapoport , Johannes Weiner , Lorenzo Stoakes , Ryan Roberts , Alistair Popple , Dev Jain , Brendan Jackman , Vlastimil Babka , Baolin Wang , Tejun Heo , Nico Pache , Suren Baghdasaryan References: <20260703-keep-subpage-private-zero-at-free-v2-0-2970fe777dd6@nvidia.com> <20260703-keep-subpage-private-zero-at-free-v2-5-2970fe777dd6@nvidia.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <20260703-keep-subpage-private-zero-at-free-v2-5-2970fe777dd6@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 88F6D140003 X-Stat-Signature: 45uarhan9hpbsxpizrfzoibmzstb7u7t X-HE-Tag: 1783090374-331106 X-HE-Meta: U2FsdGVkX1+fmrulPNX/GR036PYIfjPAGKXcCbEiaMPfzoWnXQfK7NPcdFFXF0B/CFEReu39+yFd74k7xF4kZdr9oI1NFyQ5wsWk04CvpGybEOIKEW8WXb1afldeQQLKHAqOWM74FPPW/nRkarEn7L8JeBhm5rnW8qK4hUkF62OONTi5NHZ3/cG07TGZYpEZcUR1flae7bVvh7xgv7iXEMrmFACidw+fRyjUPKOYwIuTf+Hn+Z0nDGwnMBTd8hg4s3lRMBlDZdpPpGIHLEu8dugk26u1diipYdXD5AVLqEN+gFHkjNi84j3X+Rp6a/riRxztsnE6BT/EyUjgi+4Ggs0lc4feuXAY6tWhVa6lGER1kV6J//HiaM7dyDxW/wLvHuafQOgHB2UyhvQR6SJmYoA5xYGmiHbPi3lskRc8xKtQQi45kZMZshKGl0qF1jqeLmgFiwJITnG/2gfeeOWGRXD57tUYMwNAdCqbjiEBqAVBFe1mWQhVLr8Nx9za1cQcFX3mhAKg25zE8D8Z+zBYjHfhEcdQdRfyuWOzKIq7upDUD8WiTDyFWQQGrT+uZELY+aFyL1wUE57vIzSdZTHqka5ww+UxkWfUuruX5daNECNdkMsV0Z1mZ/TDN45llDCT78LEocUY7sF7akW13G76xv3dIzLE+1AlnuZa6uL96yRcjspoDFciC01G2BEPseMIozn9znKMEgE+DwCpxD8ofhR96sliIUrvadc9Mh8+WU/HhViTW+W1pypz9Yb4clF7so5f53qkXTMmOHHTfkhYm8JHUSpHCEhLjzkFcrumKhbnHuAaP9cau+Jmn4AjHGQOgco/rsLv/WjcZHCeM8tllrMWDu7x6p0WwIf1BALIfhOL7XKw7Yn41RPFr3CIxu8M5T+bk0WssfInPhrS8xacq4l9SSQD10chdZSGPOVHKHVX+5gBUGjOT2kxskZAakVNc/3/WFkC8aw88gySOy0 6D2EwkBk vi5exmWB71IIBLpDcjGpVWse5tn6OJG4zFzZciPsXY0Kvyr4BRe92oKMJm4cZ5kG6lmQaqKLuBU0xL2UuDQlpQpiIhH21qvQ0scHIDlHf5yKWhTpvFJ3bCPPNVu1Jc3Dd40MTAdkXJ8zJqLj8M2tsN1JyZdxp/zhNm/9FgJvZ+X5+SX+ou/uSyi/pm45akqtTqXOqONq5NER90u3HS2oXMpwT/7FSYKF50BLZ5WdbZIUgdd3n4Mb4Yug1xDPfeqPPhu5NxlFUN+26Jgx+bXK9r+Wo3nY7msuZ+u8ztbUozZu35liXVfKBkZ1jqQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2026/7/3 21:47, Zi Yan wrote: > Tail pages are expected to have (and optionally be checked) zeroed > ->private when they are freed. It stays true during subsequent > reallocation, so replace the tail_page->private initialization with a > VM_WARN_ON_ONCE() in compound page preparation. > > Acked-by: Vlastimil Babka (SUSE) > Signed-off-by: Zi Yan > --- LGTM. Feel free to add: Reviewed-by: Lance Yang > mm/internal.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/internal.h b/mm/internal.h > index fa4fb69444ecd..fbd9fb84341bc 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -902,7 +902,7 @@ static inline void prep_compound_tail(struct page *tail, > { > tail->mapping = TAIL_MAPPING; > set_compound_head(tail, head, order); > - set_page_private(tail, 0); > + VM_WARN_ON_ONCE(tail->private); > } > > static inline void init_compound_tail(struct page *tail, >