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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C08D3CA0FF9 for ; Fri, 29 Aug 2025 16:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7ZezTDYPV9FY1vYbYIlP1Z79qo+TmLw98Vo74TFiYNA=; b=D9OnL3E2pI2gMbnjhr9YRskL4J 0kLurgwCJcsNgD0KBeYZFmo0UHv3C0nufgJlRQ+gaTACdDhOc/5aj4vTSPbwCV+t7uQxn6gppYA/g +5YQFU3zJwGekGEBauG9eRzHTHOpLzUB3y+ZP/4MRdfC6xxSjyuCgSGyRoC4fUy39Nrv0WYEhqvMr qT6uH0+Ps69B5FR2bjcxlnoe+K44cTZeoXLbf/sBsg4cXcn+snb8Cm+S7gILiX/q7PMqU23LD11nV ozdAgRHAP+OhBWtMKwV18eY7g3OgR3UZpZSChoxmwoVHztR2G5qDG8HfRQHlr59xqMOdYrGgmo690 M0fO9Qyg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1us2At-00000006R2d-1xdl; Fri, 29 Aug 2025 16:42:03 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1urzMX-00000005rYI-2MOH for linux-arm-kernel@bombadil.infradead.org; Fri, 29 Aug 2025 13:41:53 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:Content-Type :In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID: Sender:Reply-To:Content-ID:Content-Description; bh=7ZezTDYPV9FY1vYbYIlP1Z79qo+TmLw98Vo74TFiYNA=; b=FOoBFU96S5Q1OZ6s7iyc1W6iIA nl2N+QNNvhaxW4UQos6Qq11GuV02CKcm4n7mv2YW7j8X4x/CZO4JAymmOn64OOsOEVMzd4/FhFSeS Mn+Qa8lvb88zqKC0khbXvyOF5ekuJDwDVAKW2WalV+PnFlwp46eSca2buFNrjKCon4XJm9GSGKlPp asWDrZs6fETGP9RcOuMT1YpH9JcgBAgRIM2W1DhzJq6Xv4RBuvr+eTVTwGLIqHjS0XyHpLt4Ekyvm 5g+fRCpwV2zsaPFl8QEfj+dr/SvI3PKvQ14qfUiG/ckVVyDNloOLsfglUHftuGGH9WqKUt+YBZreW WUMTqemg==; Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by desiato.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1urzMT-000000038rK-3Pkq for linux-arm-kernel@lists.infradead.org; Fri, 29 Aug 2025 13:41:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756474906; 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=7ZezTDYPV9FY1vYbYIlP1Z79qo+TmLw98Vo74TFiYNA=; b=f98+42k7426a6CzPQitG4DnS9zPuRNCj/2cp6rT985RCqcYo/vnpZO6T/x/SB7t5eP5Tsj HVYVCVdLegLykUVu5kQakqp49TeNtQzmzkc4lUi1lNYjUYkDaoD9LecAW8SFGQAJDDcJ26 YgrLct+RrB7vq1xlQoGiX5+chGe/iGY= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1756474906; 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=7ZezTDYPV9FY1vYbYIlP1Z79qo+TmLw98Vo74TFiYNA=; b=f98+42k7426a6CzPQitG4DnS9zPuRNCj/2cp6rT985RCqcYo/vnpZO6T/x/SB7t5eP5Tsj HVYVCVdLegLykUVu5kQakqp49TeNtQzmzkc4lUi1lNYjUYkDaoD9LecAW8SFGQAJDDcJ26 YgrLct+RrB7vq1xlQoGiX5+chGe/iGY= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-449-cGzZ_I9gOgatfNpx5j7yKg-1; Fri, 29 Aug 2025 09:41:44 -0400 X-MC-Unique: cGzZ_I9gOgatfNpx5j7yKg-1 X-Mimecast-MFC-AGG-ID: cGzZ_I9gOgatfNpx5j7yKg_1756474904 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-45a1ad21752so12836455e9.1 for ; Fri, 29 Aug 2025 06:41:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756474904; x=1757079704; 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=7ZezTDYPV9FY1vYbYIlP1Z79qo+TmLw98Vo74TFiYNA=; b=ru2LWAMVQgGAKz6GIszRb5N6KoawK8zG3pAnprtMxcO5wBNbU1TfQ0n9Q5k0KXBiXT e3wGfHHo7pZyWnxS4OW14mz6hYShk8id8JIB+2DKPnYBczKPSePh2XQdsNzcen31HDRc 3UbYWr/2Jl0mDaHNYGfsNaLkMxZefaqwcU+OQe3ryWOP1C/4bQC/53nHqLBGWcFCiUYE 1bZAhN4tfmjkVNxUPSHiaPoaN/2RA156WDLdnmazeZ6cw0Lwu4NJoymKXlylRlIImjz5 lzKIBEwJTfSJSz1BDkBKnyXfv6+kjrRWDDPMBaevdqapIIjfrkCOtkwYSDrF/lfrzX17 QL9Q== X-Forwarded-Encrypted: i=1; AJvYcCXUHcZG1LmcfKk+92dj/ds/aidBmNUHo+qi8o/tfy//v63P/eOzo6VfsOCsSoQ9DxYhp22o1Wl5Gl7xUKRYD96g@lists.infradead.org X-Gm-Message-State: AOJu0YxkMr+03f4RCmQQF1TzjFZr4ev0CP092J/4dlbtOI4uJ6fdzRKs 18BGDmO/63e2a6x/QykPz32DunCRAMwgcUlwxx7a5QVbZKmo/u1NYoSTXdAVGXImORZTk3xTUfQ C0HQzF8SNPQmFpkxPmRm+sGLNBs+Y//8Yci8yskXXxU6DVldYyQvy38QxZUor3S9+sI4iDY4v4+ 4M X-Gm-Gg: ASbGnctLmI/eopwfjymK7XBhRtIC2KJkwmr0IMdXs4+GDJPSFYAFgLyzWksFZKdmK7E c4N1jTxO8GeH11RTsRTSBseXZmR3HHP+uxW60i6bZcNJY7vIIHl8jcH9xQLx857LGdLXiuLAwNp VqBe5Onb+Hq33aIDhHJwtLe+47SQssgyqfRCOEEL9UVEwNWcsfWM28oKOr2Dfs0Yh+Q6EmujvQ9 r83y7sLIvMGy/A7J3elcds1a4sSwOY2P7ISDFeujeO7XVjzaeKcqBc+ud5G7OxwkQYKE0grAyPl rgnBjHcfeB4YEuj4qtENoW/gTUggQq2wk3UL75kyjBFy4V7XOnBAH4Al3MJdLRyPIT08Jo5ATFZ N9SlkI0Qd01oES/TkgVn0KzonaM0LoejxfDBct/b3gfd4wpajYHgojPwNobYmoNfc X-Received: by 2002:a05:600c:8b0a:b0:45b:733b:1feb with SMTP id 5b1f17b1804b1-45b733b214dmr83370565e9.10.1756474903633; Fri, 29 Aug 2025 06:41:43 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHWe5EWQVl5iPDqqeubvc9kL/5oN1fdgiPPYoM9Zstyja975cqp15HWRaThC/EH89lpSzwt8Q== X-Received: by 2002:a05:600c:8b0a:b0:45b:733b:1feb with SMTP id 5b1f17b1804b1-45b733b214dmr83370155e9.10.1756474903176; Fri, 29 Aug 2025 06:41:43 -0700 (PDT) Received: from ?IPV6:2003:d8:2f1d:100:4f8e:bb13:c3c7:f854? (p200300d82f1d01004f8ebb13c3c7f854.dip0.t-ipconnect.de. [2003:d8:2f1d:100:4f8e:bb13:c3c7:f854]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3cf3458a67esm3469559f8f.62.2025.08.29.06.41.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 29 Aug 2025 06:41:42 -0700 (PDT) Message-ID: <632fea32-28aa-4993-9eff-99fc291c64f2@redhat.com> Date: Fri, 29 Aug 2025 15:41:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 18/36] mm/gup: drop nth_page() usage within folio when recording subpages To: Lorenzo Stoakes Cc: linux-kernel@vger.kernel.org, Alexander Potapenko , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , Dmitry Vyukov , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Marco Elver , Marek Szyprowski , Michal Hocko , Mike Rapoport , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan References: <20250827220141.262669-1-david@redhat.com> <20250827220141.262669-19-david@redhat.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: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Fd9vFuNDan37bzTBwPYJGo5hAPxJ-UKWy9xEmQ8OwN0_1756474904 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250829_144150_235819_48371E02 X-CRM114-Status: GOOD ( 22.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 28.08.25 18:37, Lorenzo Stoakes wrote: > On Thu, Aug 28, 2025 at 12:01:22AM +0200, David Hildenbrand wrote: >> nth_page() is no longer required when iterating over pages within a >> single folio, so let's just drop it when recording subpages. >> >> Signed-off-by: David Hildenbrand > > This looks correct to me, so notwithtsanding suggestion below, LGTM and: > > Reviewed-by: Lorenzo Stoakes > >> --- >> mm/gup.c | 7 +++---- >> 1 file changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/mm/gup.c b/mm/gup.c >> index b2a78f0291273..89ca0813791ab 100644 >> --- a/mm/gup.c >> +++ b/mm/gup.c >> @@ -488,12 +488,11 @@ static int record_subpages(struct page *page, unsigned long sz, >> unsigned long addr, unsigned long end, >> struct page **pages) >> { >> - struct page *start_page; >> int nr; >> >> - start_page = nth_page(page, (addr & (sz - 1)) >> PAGE_SHIFT); >> + page += (addr & (sz - 1)) >> PAGE_SHIFT; >> for (nr = 0; addr != end; nr++, addr += PAGE_SIZE) >> - pages[nr] = nth_page(start_page, nr); >> + pages[nr] = page++; > > > This is really nice, but I wonder if (while we're here) we can't be even > more clear as to what's going on here, e.g.: > > static int record_subpages(struct page *page, unsigned long sz, > unsigned long addr, unsigned long end, > struct page **pages) > { > size_t offset_in_folio = (addr & (sz - 1)) >> PAGE_SHIFT; > struct page *subpage = page + offset_in_folio; > > for (; addr != end; addr += PAGE_SIZE) > *pages++ = subpage++; > > return nr; > } > > Or some variant of that with the masking stuff self-documented. What about the following cleanup on top: diff --git a/mm/gup.c b/mm/gup.c index 89ca0813791ab..5a72a135ec70b 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -484,19 +484,6 @@ static inline void mm_set_has_pinned_flag(struct mm_struct *mm) #ifdef CONFIG_MMU #ifdef CONFIG_HAVE_GUP_FAST -static int record_subpages(struct page *page, unsigned long sz, - unsigned long addr, unsigned long end, - struct page **pages) -{ - int nr; - - page += (addr & (sz - 1)) >> PAGE_SHIFT; - for (nr = 0; addr != end; nr++, addr += PAGE_SIZE) - pages[nr] = page++; - - return nr; -} - /** * try_grab_folio_fast() - Attempt to get or pin a folio in fast path. * @page: pointer to page to be grabbed @@ -2963,8 +2950,8 @@ static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr, if (pmd_special(orig)) return 0; - page = pmd_page(orig); - refs = record_subpages(page, PMD_SIZE, addr, end, pages + *nr); + refs = (end - addr) >> PAGE_SHIFT; + page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); folio = try_grab_folio_fast(page, refs, flags); if (!folio) @@ -2985,6 +2972,8 @@ static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr, } *nr += refs; + for (; refs; refs--) + *(pages++) = page++; folio_set_referenced(folio); return 1; } @@ -3003,8 +2992,8 @@ static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr, if (pud_special(orig)) return 0; - page = pud_page(orig); - refs = record_subpages(page, PUD_SIZE, addr, end, pages + *nr); + refs = (end - addr) >> PAGE_SHIFT; + page = pud_page(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); folio = try_grab_folio_fast(page, refs, flags); if (!folio) @@ -3026,6 +3015,8 @@ static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr, } *nr += refs; + for (; refs; refs--) + *(pages++) = page++; folio_set_referenced(folio); return 1; } The nice thing is that we only record pages in the array if they actually passed our tests. -- Cheers David / dhildenb