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 0EE92C79FB9 for ; Thu, 10 Sep 2026 08:43:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E3D206B0092; Thu, 10 Sep 2026 04:43:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC0C76B0093; Thu, 10 Sep 2026 04:43:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8B0E6B0095; Thu, 10 Sep 2026 04:43:37 -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 9E4BF6B0092 for ; Thu, 10 Sep 2026 04:43:37 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 9A72EC0406 for ; Thu, 10 Sep 2026 08:43:36 +0000 (UTC) X-FDA: 85197214032.05.64346C8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf27.hostedemail.com (Postfix) with ESMTP id ED5DF40006 for ; Thu, 10 Sep 2026 08:43:34 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=byq2LKLh; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of chao@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=chao@kernel.org ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=byq2LKLh; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of chao@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=chao@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789029815; b=DSdVB7BBF7+cspv1owx3ydUoiUjOGrLmPJZF8qTRgAxcnnt+siWua9jM0JXSBG+e6QcS8D FGoUPltp2Soi3/a1QCu6AGeHQym0qjSGDvrybHQUbspSX5sQwCZ0MykS2r18wPecVihNOo 4x2qPZn3rZ3UYVB01VCaBW9ZXKONRpE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789029814; 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=isEbLjZPk/dWe3bh3R3NrHmu/Mf2w2fxrs7ayu2qcdw=; b=psD4z3uXTRqrdgL19UMLYMNF2g7vDJJwcKzqcv9WbqgM3jCoSCX8L/0sdg2Kpwwsq2LM9C UIDlSS5SX4dFFh2ZWx11t8rkRh7u+/5YCoq9ZiYubnvjzT3XGVFmbR+eWJZu1SXRxE3Q45 7U53/S75Zx1gfal5N7Wo+9pLYffjT2U= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 302A2601F1; Thu, 10 Sep 2026 08:43:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29E2E1F000FF; Thu, 10 Sep 2026 08:43:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789029813; bh=isEbLjZPk/dWe3bh3R3NrHmu/Mf2w2fxrs7ayu2qcdw=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=byq2LKLh5wTPUorRM31M4sIDve1usn/sR9AsugS+bvOrGQ0q2EKGgRVXELonBPepU Gn/ViuRSmp4XQJIJwRhWXFWkxkPKm2DGlFogH16zZxZ4iQ+ZT657K+3xZK25i/81Ba /x9+5v5YgJ/Ss1CNrGmD1seqX2AeaYn3Rr6m+Y3DTYKPFs/q+eB8Z4G12iJU0ttEVS FO3rPrBkfjpUK1Xapvv8Y6OhQTd8GKz4pDNUe7SJmYLqM0XOoH+1pPTyY8r0Qp7xJI usAbolvU3Qop8LaA1p6AQexHn/SCerYpxEyDLJh0l50wTRBXHITBGPYo166RCBroFP bfg4rcYtiE2Qw== Message-ID: Date: Thu, 10 Sep 2026 16:43:27 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH v3 06/14] f2fs: stop using PG_private To: "David Hildenbrand (Arm)" , 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 References: <20260907-remove-pg_private-v3-0-6ae22f9d9272@nvidia.com> <20260907-remove-pg_private-v3-6-6ae22f9d9272@nvidia.com> <7e11c56d-05e6-48f0-b5b8-b4a0e18ddc1d@kernel.org> <520b6aca-b515-4720-977f-1adb484f2e08@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: <520b6aca-b515-4720-977f-1adb484f2e08@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: ED5DF40006 X-Stat-Signature: 3c6s6qryph1z7eywio4jwzwtnj3iaiz6 X-Rspamd-Server: rspam01 X-HE-Tag: 1789029814-400641 X-HE-Meta: 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 2fofIL6o 7NXtOo3iGCLY4x+JhzJ+R/L51s+K9ip1CUmBEqzMPgibdfbvWk+sCkyt/fJg/4pX1jE085+Ttx+d7OEdoviqvOoPbdu59fW4hAnMuAKuPFnOSiJnaY1m0Hfy2ngFy58E5saG0bOnjLhq4Dpv8XgHdvfGV6WRFIVb8z6qOWZblT0zwSAmk9qgX+jz3mSfM7L1dneJJO+osAlCrlWv0TChyXQXWyrR1QB1/A8olROOxtyrrkHsuS7wIcV32P7YVW8W+SMgw5914HLHutRWxGZubZzMXSmmqHvARXe+FbYWw1j8RCVxqD92rPFfVBehn5M6wjARxsLOZQe/gz4yNOYWR6S5aMi8xEmiyXvBaCW0Ow8H+6/9P13++YhzzUQktEXnFnB9V Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/10/26 15:34, David Hildenbrand (Arm) wrote: > On 9/10/26 04:41, Chao Yu wrote: >> On 9/8/26 23:47, David Hildenbrand (Arm) wrote: >>> On 9/8/26 04:56, Zi Yan wrote: >>>> f2fs sets its PAGE_PRIVATE_* flags in page->private and checking >>>> page->private != NULL is equivalent to checking PG_private. Change >>>> PagePrivate() to page_private(). Meanwhile, in set_page_private_##name(), >>>> page->private is first set to 0/NULL before an PAGE_PRIVATE_* flag is set, >>>> but it can cause confusion when PG_private is removed and >>>> page->private != NULL is used instead. Change it to initialize >>>> page->private to PAGE_PRIVATE_NOT_POINTER instead and retain the original >>>> semantics. >>>> >>>> It prepares for a future commit that removes PG_private. >>>> >>>> No functional change intended. >>>> >>>> Assisted-by: Claude:claude-opus-4-8 >>>> Assisted-by: Codex:gpt-5 >>>> To: Jaegeuk Kim >>>> To: Chao Yu >>>> Cc: linux-f2fs-devel@lists.sourceforge.net >>>> Cc: linux-kernel@vger.kernel.org >>>> Acked-by: Usama Arif >>>> Acked-by: Chao Yu >>>> Signed-off-by: Zi Yan >>>> --- >>>> fs/f2fs/f2fs.h | 8 ++++---- >>>> 1 file changed, 4 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>> index 9940a6cecf1a2..2f7ab5888b078 100644 >>>> --- a/fs/f2fs/f2fs.h >>>> +++ b/fs/f2fs/f2fs.h >>>> @@ -2691,7 +2691,7 @@ static inline bool folio_test_f2fs_##name(const struct folio *folio) \ >>>> } \ >>>> static inline bool page_private_##name(struct page *page) \ >>>> { \ >>>> - return PagePrivate(page) && \ >>>> + return page_private(page) && \ >>>> test_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)) && \ >>>> test_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \ >>>> } >>>> @@ -2710,9 +2710,9 @@ static inline void folio_set_f2fs_##name(struct folio *folio) \ >>>> } \ >>>> static inline void set_page_private_##name(struct page *page) \ >>>> { \ >>>> - if (!PagePrivate(page)) \ >>>> - attach_page_private(page, (void *)0); \ >>>> - set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)); \ >>>> + if (!page_private(page)) \ >>>> + attach_page_private(page, \ >>>> + (void *)BIT(PAGE_PRIVATE_NOT_POINTER)); \ >>>> set_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \ >>>> } >>> >>> Very weird interface. Why do we even need the page-based interface still? >>> >>> $ git grep -E "(set|clear)_page_private" >>> compress.c: clear_page_private_gcing(cc->rpages[i]); >>> compress.c: set_page_private_gcing(cc->rpages[i]); >>> compress.c: clear_page_private_gcing(cic->rpages[i]); >>> f2fs.h:static inline void set_page_private_##name(struct page *page) \ >>> f2fs.h:static inline void clear_page_private_##name(struct page *page) \ >>> >>> Seeing code like: >>> >>> clear_page_private_gcing(cc->rpages[i]); >>> if (folio_test_writeback(page_folio(cc->rpages[i]))) >>> end_page_writeback(cc->rpages[i]); >>> >>> Makes me wonder whether we can just use the folio helper instead? >>> >>> In f2fs_iget(), we enable large folios only when !f2fs_compressed_file(inode). >>> >>> So naive me would assume that we can just get rid of the >>> set_page_private_/clear_page_private_ stuff entirely. >> >> David, >> >> Thanks for the patch, at a glance, it seems fine, can you please send >> a formal patch? then we can apply to dev-test for test. > > I'm hoping Zi will drag that along as part of this patch set. Is this fine or do Oh, I see. > you want it sent as a complete standalone patch (will make merging Zi's series > slightly more complicated :) ). I think sending as a separated patch based on Zi Yan's patch is fine, since the purpose of this patch is a little different from Zi's one. Note that: ("f2fs: stop using PG_private") has been merged in https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/log/?h=dev-test, Thanks,