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 6E80CCA0FFE for ; Tue, 2 Sep 2025 10:07:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C86F38E000B; Tue, 2 Sep 2025 06:07:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C0FD18E0001; Tue, 2 Sep 2025 06:07:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB0E18E000B; Tue, 2 Sep 2025 06:07:01 -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 906DF8E0001 for ; Tue, 2 Sep 2025 06:07:01 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1925A5CE4C for ; Tue, 2 Sep 2025 10:07:01 +0000 (UTC) X-FDA: 83843881842.14.A7F285E Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf21.hostedemail.com (Postfix) with ESMTP id DB94A1C000B for ; Tue, 2 Sep 2025 10:06:58 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LY83kQQv; spf=pass (imf21.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756807619; 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=yQBjL6Mz1yywDE3JBeNxw+HRiz9wSeKoX5ELaLVEmP0=; b=u/jkI3ZfhdfNtFFoXEASWMkA/H/v1zznT0qttHnE4vJbRhaFaQhuVK4jXn0pCV2x5IdBmW 3L01P2LxvS3wiuQxh/OQ5TssSLHDxSH9T8uJ/zG3Eti9yPv5jXeSZ82+8GLVfWYtdmXgnj Yq/6oPUrHxTEtbXUc9dadmlTuJRkaxo= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LY83kQQv; spf=pass (imf21.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756807619; a=rsa-sha256; cv=none; b=IfK8fF8+VMArhrKBKxkL8SqYWye5YP2Bj85oiAeqEn8lVYeakaO8po+6iIrLHqUxj2a1H2 o7pKzOapY3KG3DpSePA9aDhA3yqLsOIuY49x8SL5X47EC0OcS+FvpeV48IkslcRW8bF7xr sKeGqbG7+7tBJEUVGQ+8lMPnhiabPuw= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756807618; 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:autocrypt:autocrypt; bh=yQBjL6Mz1yywDE3JBeNxw+HRiz9wSeKoX5ELaLVEmP0=; b=LY83kQQvetausL4t2XKXQqjAgpUCWpVxI0PLM1Ehn2Hy2a5OII4lxhee042RGWcsPRdZHZ gdd1jueyIJpAe+MkL2RtLcN8Xs3rqrdv5rs8ytYbZ1YihJgdLWyQkUnWIe/D+Z63s7uYfm pmODCzQx15yLehy6a0KekFlS7FwAFrs= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-587-voZYaiJZOqiSaNl3Re8cbQ-1; Tue, 02 Sep 2025 06:06:57 -0400 X-MC-Unique: voZYaiJZOqiSaNl3Re8cbQ-1 X-Mimecast-MFC-AGG-ID: voZYaiJZOqiSaNl3Re8cbQ_1756807616 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3d17731acb6so2762282f8f.3 for ; Tue, 02 Sep 2025 03:06:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756807616; x=1757412416; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=yQBjL6Mz1yywDE3JBeNxw+HRiz9wSeKoX5ELaLVEmP0=; b=dzrRprwN7fj13NmbWO9GWCxbkfmi/+Em6/rsaMULCOZ3uN9XqdSWDXDRG1e5JCBc4u nKzrC9VXhyz4HG7zbn+vdcdj63pUAO8I+kUz3nfFFGrJLVtjUj1oToewrle6aJ+/IvOe eza8vPZoVxBvwQ56vRs7TNJqXhG526cNVgoMsgKCB7J6uj1FPkeM9bu1GJEft26IUvik McA944l84HKpWyRYZ7C6vvHmYuvh8YyyDvb15b6oyNY5QgCz/3pxoJvHKtW4flAloJTz hQrFwNTU2QhCz/QH69XLQYWrTFtRrVjVUrT4SpDNabyknYfTupWH+7+pt2YcaR27gMQ5 lGNg== X-Forwarded-Encrypted: i=1; AJvYcCVqSFnQ1V/kIGptdiw3UAFS1xkN2iN9Ytxha/ZfbIyf6ytlwxnW17qjbv75oW4DpF3ZLFlsgY/g6Q==@kvack.org X-Gm-Message-State: AOJu0YxF6dvCHLWtMT9r87agByoPIwZaUvotGE7vGFdsahQ7VHS4r43P bZHtyBZ4l0FzTgLU5hKFvmFEcURmZ4P8BKDHUODPNxZMKXiTDuuHB2J5Jw7RdtyroT5KY9OBW6I tgY0iQN3CadXMtrAL9FjDOFaS3nO1RyAapp2v5eWLq/uDPKapOug1 X-Gm-Gg: ASbGncutypGAZJ/K1owIz1Tl7eLkRMzXcZeddi6rgt62D/xLTTmqdIsoiZ10H/l5mz7 ysnnnQe/X1JFPLquCdlV9a5klrQvhQ2t8Qj1HA+OYRg4d25ue9KwEw6YiJsKk6YHtmgnPFRfOUO SscirrE/NrnKInWwTRIRQHAc9/n2BokamfOGTm+CVr+bLIfpZJtHAXU8I1SnRP17t7PETc2CWZj nGLoGrTogMgUyEd+p0vehGG99+GCrarn9rqRwyVfz3M+WOjlBxdygGdSuzUdcV0BFXeW/xaszpp LcOb9FAr19zDmuoTyFdlQ+fs8Q8qXQBEJHY0v8Ty7Kfahhc5qicosK18YGarZRDol0qtcgBmrsG QsnYqDUSBj9foykSY4hL/DvcSz/acQX/yOvaCRs5C930u/c8vL3qnvyYHQfv8uzJz5oI= X-Received: by 2002:a05:6000:2307:b0:3ce:f9b7:4db with SMTP id ffacd0b85a97d-3d1de6a8dc5mr9225610f8f.24.1756807615825; Tue, 02 Sep 2025 03:06:55 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFN/f0bU7xidso2QGDLy/JmGY1w4j+2LPFKqk9bXnHh6iqP3ESV1ILbYveFavO2boVsWDG8fQ== X-Received: by 2002:a05:6000:2307:b0:3ce:f9b7:4db with SMTP id ffacd0b85a97d-3d1de6a8dc5mr9225572f8f.24.1756807615283; Tue, 02 Sep 2025 03:06:55 -0700 (PDT) Received: from ?IPV6:2003:d8:2f1f:3f00:731a:f5e5:774e:d40c? (p200300d82f1f3f00731af5e5774ed40c.dip0.t-ipconnect.de. [2003:d8:2f1f:3f00:731a:f5e5:774e:d40c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45b945332adsm36060615e9.4.2025.09.02.03.06.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Sep 2025 03:06:54 -0700 (PDT) Message-ID: Date: Tue, 2 Sep 2025 12:06:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/9] mm, swap: use unified helper for swap cache look up To: Kairui Song , linux-mm@kvack.org Cc: Andrew Morton , Matthew Wilcox , Hugh Dickins , Chris Li , Barry Song , Baoquan He , Nhat Pham , Kemeng Shi , Baolin Wang , Ying Huang , Johannes Weiner , Yosry Ahmed , Lorenzo Stoakes , Zi Yan , linux-kernel@vger.kernel.org References: <20250822192023.13477-1-ryncsn@gmail.com> <20250822192023.13477-2-ryncsn@gmail.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+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: <20250822192023.13477-2-ryncsn@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: XiDiTA43apKnk4nosShqY4Z1KGnPTNWL8Px99EoZNG8_1756807616 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: DB94A1C000B X-Stat-Signature: stfc383rzn9pijdz67f5kpygk41bssqb X-Rspam-User: X-HE-Tag: 1756807618-805372 X-HE-Meta: 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 qDv+lyIa Ij2W2VO9gxVE2j7sndyv17+NfZUl0bhqm1uV7V0QuY0rzqMQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 22.08.25 21:20, Kairui Song wrote: > From: Kairui Song > > Always use swap_cache_get_folio for swap cache folio look up. The reason > we are not using it in all places is that it also updates the readahead > info, and some callsites want to avoid that. > > So decouple readahead update with swap cache lookup into a standalone > helper, let the caller call the readahead update helper if that's > needed. And convert all swap cache lookups to use swap_cache_get_folio. > > After this commit, there are only three special cases for accessing swap > cache space now: huge memory splitting, migration and shmem replacing, > because they need to lock the Xarray. Following commits will wrap their > accesses to the swap cache too with special helpers. > > Signed-off-by: Kairui Song > --- > mm/memory.c | 6 ++- > mm/mincore.c | 3 +- > mm/shmem.c | 4 +- > mm/swap.h | 13 +++++-- > mm/swap_state.c | 99 +++++++++++++++++++++++------------------------- > mm/swapfile.c | 11 +++--- > mm/userfaultfd.c | 5 +-- > 7 files changed, 72 insertions(+), 69 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index d9de6c056179..10ef528a5f44 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -4660,9 +4660,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > if (unlikely(!si)) > goto out; > > - folio = swap_cache_get_folio(entry, vma, vmf->address); > - if (folio) > + folio = swap_cache_get_folio(entry); > + if (folio) { > + swap_update_readahead(folio, vma, vmf->address); > page = folio_file_page(folio, swp_offset(entry)); > + } > swapcache = folio; > > if (!folio) { > diff --git a/mm/mincore.c b/mm/mincore.c > index 2f3e1816a30d..8ec4719370e1 100644 > --- a/mm/mincore.c > +++ b/mm/mincore.c > @@ -76,8 +76,7 @@ static unsigned char mincore_swap(swp_entry_t entry, bool shmem) > if (!si) > return 0; > } > - folio = filemap_get_entry(swap_address_space(entry), > - swap_cache_index(entry)); > + folio = swap_cache_get_folio(entry); > if (shmem) > put_swap_device(si); > /* The swap cache space contains either folio, shadow or NULL */ > diff --git a/mm/shmem.c b/mm/shmem.c > index 13cc51df3893..e9d0d2784cd5 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -2354,7 +2354,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, > } > > /* Look it up and read it in.. */ > - folio = swap_cache_get_folio(swap, NULL, 0); > + folio = swap_cache_get_folio(swap); > if (!folio) { > if (data_race(si->flags & SWP_SYNCHRONOUS_IO)) { > /* Direct swapin skipping swap cache & readahead */ > @@ -2379,6 +2379,8 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, > count_vm_event(PGMAJFAULT); > count_memcg_event_mm(fault_mm, PGMAJFAULT); > } > + } else { > + swap_update_readahead(folio, NULL, 0); > } > > if (order > folio_order(folio)) { > diff --git a/mm/swap.h b/mm/swap.h > index 1ae44d4193b1..efb6d7ff9f30 100644 > --- a/mm/swap.h > +++ b/mm/swap.h > @@ -62,8 +62,7 @@ void delete_from_swap_cache(struct folio *folio); > void clear_shadow_from_swap_cache(int type, unsigned long begin, > unsigned long end); > void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry, int nr); > -struct folio *swap_cache_get_folio(swp_entry_t entry, > - struct vm_area_struct *vma, unsigned long addr); > +struct folio *swap_cache_get_folio(swp_entry_t entry); > struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, > struct vm_area_struct *vma, unsigned long addr, > struct swap_iocb **plug); > @@ -74,6 +73,8 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, > struct mempolicy *mpol, pgoff_t ilx); > struct folio *swapin_readahead(swp_entry_t entry, gfp_t flag, > struct vm_fault *vmf); > +void swap_update_readahead(struct folio *folio, struct vm_area_struct *vma, > + unsigned long addr); > > static inline unsigned int folio_swap_flags(struct folio *folio) > { > @@ -159,6 +160,11 @@ static inline struct folio *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, > return NULL; > } > > +static inline void swap_update_readahead(struct folio *folio, > + struct vm_area_struct *vma, unsigned long addr) > +{ > +} > + > static inline int swap_writeout(struct folio *folio, > struct swap_iocb **swap_plug) > { > @@ -169,8 +175,7 @@ static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entr > { > } > > -static inline struct folio *swap_cache_get_folio(swp_entry_t entry, > - struct vm_area_struct *vma, unsigned long addr) > +static inline struct folio *swap_cache_get_folio(swp_entry_t entry) > { > return NULL; > } > diff --git a/mm/swap_state.c b/mm/swap_state.c > index 99513b74b5d8..ff9eb761a103 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -69,6 +69,21 @@ void show_swap_cache_info(void) > printk("Total swap = %lukB\n", K(total_swap_pages)); > } > > +/* While at it, proper kerneldoc? /** etc. Also documenting that it will only return a valid folio pointer or NULL > + * Lookup a swap entry in the swap cache. A found folio will be returned > + * unlocked and with its refcount incremented. > + * > + * Caller must lock the swap device or hold a reference to keep it valid. > + */ > +struct folio *swap_cache_get_folio(swp_entry_t entry) > +{ > + struct folio *folio = filemap_get_folio(swap_address_space(entry), > + swap_cache_index(entry)); > + if (!IS_ERR(folio)) > + return folio; > + return NULL; Maybe better as (avoid one !) if (IS_ERR(folio)) return NULL; return folio; or simply return IS_ERR(folio) ? NULL : folio. > +} > + > void *get_shadow_from_swap_cache(swp_entry_t entry) > { > struct address_space *address_space = swap_address_space(entry); > @@ -273,54 +288,40 @@ static inline bool swap_use_vma_readahead(void) > } > > /* > - * Lookup a swap entry in the swap cache. A found folio will be returned > - * unlocked and with its refcount incremented - we rely on the kernel > - * lock getting page table operations atomic even if we drop the folio > - * lock before returning. > - * > - * Caller must lock the swap device or hold a reference to keep it valid. > + * Update the readahead statistics of a vma or globally. > */ > -struct folio *swap_cache_get_folio(swp_entry_t entry, > - struct vm_area_struct *vma, unsigned long addr) This also sounds like a good kerneldoc candidate :) In particular, documenting that it is valid to pass in vma == NULL (in which case the addr is ignored). > +void swap_update_readahead(struct folio *folio, > + struct vm_area_struct *vma, > + unsigned long addr) > { Apart from that LGTM. -- Cheers David / dhildenb