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 52174C61DB9 for ; Thu, 27 Aug 2026 16:41:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 53ED76B0098; Thu, 27 Aug 2026 12:41:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4C83E6B00A2; Thu, 27 Aug 2026 12:41:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3B9946B00A6; Thu, 27 Aug 2026 12:41:28 -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 076D86B0098 for ; Thu, 27 Aug 2026 12:41:27 -0400 (EDT) Received: from smtpin15.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 93E3F1C0030 for ; Thu, 27 Aug 2026 16:41:27 +0000 (UTC) X-FDA: 85147615014.15.E97D4FE Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf24.hostedemail.com (Postfix) with ESMTP id DA50D180009 for ; Thu, 27 Aug 2026 16:41:25 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=b6xaLIzY; spf=pass (imf24.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 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=1787848885; b=a+80M9VKqUOpFK/WcG95Pn9Aj4spGuiiXsCenpDtwa0rw2iR5nn1v56s1ROJEuiuxCMaKH uGarcvd4u/3PMYqUQXWLEilWejzrbUeOH0hN7AXh9MQ4P6uROqWjxAIb3vtJrRIowgr7Qo EXssBa/fnllUpZIEqDZfOb2v5zkZq1o= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=b6xaLIzY; spf=pass (imf24.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 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=1787848885; 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=bCC2CkHOGwlKpi+16PhEFCGSE3IEc/igKIbUU+uMh80=; b=XM9Owe/lCQ7ILyYBqi0BRqGJrFAg9RW6C6jfiX+sUlL+IdKNJ6Q37AbyGyVoQshYtsPhWP vy1JVlnRaCPbkca8wD6/pLq4Mfk7kYdwkKDo18CDV6NEop3N2GlXWhAD+ieXUqEnfooybE qNyndfzJiHdggCZOZomtwi5dzlx7hL0= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 20E67600D2; Thu, 27 Aug 2026 16:41:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A42D1F000E9; Thu, 27 Aug 2026 16:41:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787848884; bh=bCC2CkHOGwlKpi+16PhEFCGSE3IEc/igKIbUU+uMh80=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=b6xaLIzYah4sJVfBReqcEi5FQT78DXP9WZ9cbcGxuv06r/N6WfCkWKg/xp1UBhRPP Hyk0oWIix07jekjKLzCKIEqj/ottYR2QZR0DgQwyCNTM098m2ur1cma/eJM8+jCjmZ fBaL8WR3ptaZK/QPO5BETCTgamTASyLgnU8jhziDK4faVCLPUjSEQAjsuhMIizvrk9 bDXmGFi0V+2lKxGqX8tM5BvqNbSj2r13pkPpZtQRn+spAXvMeA5ao70UJfpt6civlM Qj7ZzlWe7VA7pdpK5Pc07Zb8ijR8Bi7vrzKDFX9/jt9uQzIgEVQoccxBAJnfIpIlUK hdkd4kxMJm2Yw== Message-ID: <5ee65970-abb9-47ea-b548-5430b382cf7c@kernel.org> Date: Thu, 27 Aug 2026 18:41:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 11/18] mm/huge_memory: allow splitting mappingless swap cache folios To: kasong@tencent.com, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Chris Li , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Shivam Kalra , Kairui Song References: <20260821-swap-thp-cleanup-v3-0-9b43f5163238@tencent.com> <20260821-swap-thp-cleanup-v3-11-9b43f5163238@tencent.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: <20260821-swap-thp-cleanup-v3-11-9b43f5163238@tencent.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DA50D180009 X-Stat-Signature: tqj8oofxmswobog755z34oiypbpxogx5 X-Rspam-User: X-HE-Tag: 1787848885-588875 X-HE-Meta: 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 JH3cziAe 5QfTnlljaOfuMnoTu/PXbvMy4NkqiE6xnwXqWUw5SNOchwMPGDM7uHD+aY4PLnebWWgnq9sZmWFz7G31Uw/dboRNaVgMHCYwFNbgnTITSSxul6QoZujUXFS93v4C/4Bpt4HaNp81aVA/ok1Bi93r4ucpr2Tppb4Ih74HnppWEow3N6C8rZpPYjpObPhoqLk293M1cqddcz/fLo6vFk2LPHD3JUHY9xSF808FF+v2ca8nRnFcFJ3cdoACSMEojXFPea//i2v5k1hjS0Yu5oCk+e13nhgk31bJBlmJ8VzSoOyPv9zvGYknF95QP8A== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > + if (anon_vma) { > if (!ret && !folio_is_device_private(folio)) > ttu_flags = TTU_USE_SHARED_ZEROPAGE; > remap_page(folio, 1 << old_order, ttu_flags); > @@ -4259,6 +4261,7 @@ static int __folio_split(struct folio *folio, unsigned int new_order, > struct page *split_at, struct page *lock_at, > struct list_head *list, enum split_type split_type) > { > + bool is_swapcache = folio_test_swapcache(folio); > struct folio *end_folio = folio_next(folio); > bool is_anon = folio_test_anon(folio); > int old_order = folio_order(folio); > @@ -4285,8 +4288,11 @@ static int __folio_split(struct folio *folio, unsigned int new_order, > } > > if (is_anon) > - ret = __folio_split_unmap_and_freeze_anon(folio, new_order, split_at, true, > - true, list, split_type); > + ret = __folio_split_unmap_and_freeze(folio, new_order, split_at, true, > + true, list, split_type); > + else if (is_swapcache) > + ret = __folio_split_unmap_and_freeze(folio, new_order, split_at, true, > + false, list, split_type); These two boolean parameters are really a pain. There must be a better way. Also, I don't like that __folio_split_unmap_and_freeze() sounds generic again. There must be a better way for that as well. We had a clean split and now we mangle it again. ... but I am just before my PTO and out of puff, so others can brainstorm on how to do this cleaner :) -- Cheers, David