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 D7E7DCD3436 for ; Fri, 8 May 2026 07:01:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C71D86B010D; Fri, 8 May 2026 03:01:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C490D6B010E; Fri, 8 May 2026 03:01:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B5F436B010F; Fri, 8 May 2026 03:01:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A4EB76B010D for ; Fri, 8 May 2026 03:01:57 -0400 (EDT) Received: from smtpin25.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 4971B1A0761 for ; Fri, 8 May 2026 07:01:57 +0000 (UTC) X-FDA: 84743357874.25.8C575A4 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) by imf05.hostedemail.com (Postfix) with ESMTP id 4904F100002 for ; Fri, 8 May 2026 07:01:55 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=iha2P92R; spf=pass (imf05.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.188 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1778223715; 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=NjihaeD76Jsi8Lwgt5xatfktO5NhR9x51duFuCUS48I=; b=vEIOpYun1rTXkhGvhdmqdvIzWAuifKE8fS5Daz9JyC+WEDUxFZXAqr7vlmP7LPTg8meydC 71VQzYc2vYeY+QngbKLXLmB+RPIyence0isa29hIEwDzv4hhol3T62N5oh2nq2ps4XFvuo VNuMiup50PIyxz/QTOT1mrR7zuTh/48= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1778223715; a=rsa-sha256; cv=none; b=rywzl1Xm6dx3CX0I90tVRblq5eG56RxuU+ybdgbm97S9IZGv4vDm2R2kW537VvK6iZMwp1 5QbivMMTM+5Z2Ri7PeeLR6YYyFeZH44yfcEqMIc3PQ7lZNmPrU8isDU1ifEjTMPZOrbnFZ 1zUefd3edkXCG369/aK89ENDx+o+rQM= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=iha2P92R; spf=pass (imf05.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.188 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1778223712; 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=NjihaeD76Jsi8Lwgt5xatfktO5NhR9x51duFuCUS48I=; b=iha2P92RrzX66oAtKsbukb/2Sw0Jn2it2q2sfp/ztwpYbr2+hf03kOW505Mxcb1lEHH1Sa H1TGMGI6zu6hxwo9RaHB1CDDQ/KHNSUQH0b270vEUH3aUWr6DvDhuP75QME4ASoJjvxk6b dgjJoO36+YMmfKBxkU3JaBgkcX19mnE= From: Lance Yang To: ziy@nvidia.com Cc: akpm@linux-foundation.org, david@kernel.org, willy@infradead.org, songliubraving@fb.com, clm@fb.com, dsterba@suse.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, ljs@kernel.org, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v5 09/14] mm/truncate: use folio_split() in truncate_inode_partial_folio() Date: Fri, 8 May 2026 15:01:27 +0800 Message-Id: <20260508070127.18666-1-lance.yang@linux.dev> In-Reply-To: <20260429153538.727855-5-ziy@nvidia.com> References: <20260429153538.727855-5-ziy@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 4904F100002 X-Stat-Signature: fbci5mecaa75so46h9cy456c8xqqbipm X-Rspam-User: X-HE-Tag: 1778223715-398365 X-HE-Meta: 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 2vziiDfz cKo/cMS5klU4nrgYZ280uidHyj0vgmv+2+i1rQroq0PIQZeG0M3QlkSOTu31ce5HPB4psNSdTTjuqDpOmTbeE4Af6MM2zHreJccoENe1JqtbswpAomsYLTeawjwt3QvU2rMLuccjOhCzqcT46ByObP9L012U8KYBN4Q/huGs2Cik45PdM0H8OQTJZ8fERQqzMg8NkLs8rPQ7XTOUYtV7qUGtxs4rQXxAtJ/jTGP8U5v/sPI3Fftsjgbwotj5HFBY/2MWlwcdEXZvCf2JxecMBwEtIBYsHXcglK+KQl7CC2OKG3OrZvHB0a7dQFw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Apr 29, 2026 at 11:35:32AM -0400, Zi Yan wrote: >After READ_ONLY_THP_FOR_FS is removed, FS either supports large folio or >not. folio_split() can be used on a FS with large folio support without >worrying about getting a THP on a FS without large folio support. > >When READ_ONLY_THP_FOR_FS was present, a PMD large pagecache folio can >appear in a FS without large folio support after khugepaged or >madvise(MADV_COLLAPSE) creates it. During truncate_inode_partial_folio(), >such a PMD large pagecache folio is split and if the FS does not support >large folio, it needs to be split to order-0 ones and could not be split >non uniformly to ones with various orders. try_folio_split_to_order() was >added to handle this situation by checking folio_check_splittable(..., >SPLIT_TYPE_NON_UNIFORM) to detect if the large folio is created due to >READ_ONLY_THP_FOR_FS and the FS does not support large folio. Now >READ_ONLY_THP_FOR_FS is removed, all large pagecache folios are created >with FSes supporting large folio, this function is no longer needed and all >large pagecache folios can be split non uniformly. > >Signed-off-by: Zi Yan >--- With that gone, large page-cache folios should only exsit on mappings that support large folios, so folio_split() with mapping_min_folio_order() is enough :) LGTM, feel free to add: Reviewed-by: Lance Yang