From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A11B12E9EAD for ; Thu, 11 Sep 2025 12:04:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757592273; cv=none; b=OVjrZ9ZPxgg0Hzt+0vhMb/6eGs9gQmuOmk6qEjulTn6kLyBrzl4Raha1a2RIBUzbhJzm5g5ncsR2G4fvyL6SPDFgpo1kuNXGZX2qv8GSu9DW3drpcTkurYI7hHSNB7jrF7Q7VNQDnrpi/3vufpZwcDrdCideAAiu77ymCHlRhNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757592273; c=relaxed/simple; bh=Wt0bC5mvDF/uHEWIdzjdJu0LeGAa2X3RPBVPJei0lk8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AuLSROuwCoddnt1Myw3a1/NJnkuCj0gIZUrpQQQVZU3PH4FVCGP5+iwyfjPdfgHebK4ti6Gz07F0EvCGg0el8HzR0aFVvFNbapVWAyDPw/joHU8YTew1P1v2E0Xfcg035NCDYXphjDe8DKQgHWJdYBTn7rm8sOcVrceJiFrPGz8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=BEICEPI+; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BEICEPI+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757592270; 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=EuZPErlVPfP4Zi7OehwAoScM8rfscgPVz8IjeFSlZfc=; b=BEICEPI+XKEA1tgJ61XnCtifDdNA0RJaEhVHg29X8Jyr5qs1Wv+sDcCzgWLKCp9JhVzO90 6Uz977rR0LxC9CTD5IjrmA+4B1llAZnpQIn5Zv5ueAoNUru6FC0UW6DFTBMaYRNDOGc4Ld t2IB/ET8P35zeVNZ1a8Q+rqgEgNNLdA= 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-411-OBZ6-pWENc-5EUAGwnApxw-1; Thu, 11 Sep 2025 08:04:29 -0400 X-MC-Unique: OBZ6-pWENc-5EUAGwnApxw-1 X-Mimecast-MFC-AGG-ID: OBZ6-pWENc-5EUAGwnApxw_1757592268 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-45e037fd142so4709315e9.3 for ; Thu, 11 Sep 2025 05:04:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757592268; x=1758197068; 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=EuZPErlVPfP4Zi7OehwAoScM8rfscgPVz8IjeFSlZfc=; b=h7qtw5unv2NiXyci7Mm0iHBOTza4yIAP82D5wCllOvXFuKxqihR3VQAmA+Yae3rDTF SAWxw4FAMKp99TjXXaypjyasoceUrBqbJiJiurV1FM5kdRV9dX0TqmEA79MO/VDb79E2 M4zY22M52PTL5qkXDmZN+Tn83lCIdmJXn4UfRbLy/duigMm+7fYuiH40HRmKbPHmHVFk inGaPAyMiLD/h+MypjB6mVqF9HAe8diQznfW42bVCKNyrhOTh0JAwxyHqwE6Jp7GJpT2 c4p3c4IZiGZT9IANvxVrgVyLs8NxSbWvC9duexANnoCuMLewLt+U3VWV5XWP5PRPPGRP B9TA== X-Forwarded-Encrypted: i=1; AJvYcCWJiLWp1wHhESaLnaunjvVYoXhkSp3sxByNPZBOWwn1FqmABZW1OpxQHyxk9PGIjtlLOFZtYBHOlDrSZtY=@vger.kernel.org X-Gm-Message-State: AOJu0Yz9O1QgYr6Nb/x7oXsxUyLj5MBm0gyxrlH/hqbBnswQ11xacRAz aA/0MTQy2HSadIyJuqHGRqm6aeJH7EHWmxB0aTOicxdovA7rPIZdK3HFBZ5tcClYWQWB6CaWufF LszgFelDschuw/5FN4iVdt0EyrNNC+dS+8ePN1FGq+088Kk+uJjYktiYwBGg9UJB+mA== X-Gm-Gg: ASbGncsuyc05qWkCzahTw+tyrh4tvpzMCedZ1nvTu0d/VXJGcsFC/P0Q1EQS0PgOjMH h4OpyBfxUtOpQDlPRQ1zc2rWwbVZSszB8YkK2KSQVMYb3MxK7DIzEeCeKRoO4uEGoJk46aciaCk s1RIhFC2xNnUlX5XZFTIvIam/rlYXb7tlpC3RDCTJUfJgYmOHI59HzHwZeXpurhQgXCSVmNCG7y M/TrluL2ltV+vv5R2f2O83q2eo4AnW3epRhH1BIwStyJHoOIqX2GnLHrBuPQNNG7FMXo2KtjxKW xe14hjvjAJe9YXaHPjMl3EU6IeDLRXSTS2kKCEIMxNnFPldqPIBj+BSN85VPM2hFLrCc7ByAgGo VOkmFZYvDQ4Mz6WQoVLTzLskzddfcqFd2NHX8Rz9zSS3Q/h7IUMhR/v+txxnFU8PF2+0= X-Received: by 2002:a05:600c:17d8:b0:45e:598:90b0 with SMTP id 5b1f17b1804b1-45e05989245mr12298565e9.9.1757592268215; Thu, 11 Sep 2025 05:04:28 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE8gojWv48o7hPnSlLmGoQLH2lzL/OCbhuDjeyev+XCC7h++EYG0R0k7MthrD+iGwxnZwbgRA== X-Received: by 2002:a05:600c:17d8:b0:45e:598:90b0 with SMTP id 5b1f17b1804b1-45e05989245mr12298135e9.9.1757592267679; Thu, 11 Sep 2025 05:04:27 -0700 (PDT) Received: from ?IPV6:2003:d8:2f42:b000:db8b:7655:f60f:812b? (p200300d82f42b000db8b7655f60f812b.dip0.t-ipconnect.de. [2003:d8:2f42:b000:db8b:7655:f60f:812b]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45e0187f0a7sm13295915e9.3.2025.09.11.05.04.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Sep 2025 05:04:27 -0700 (PDT) Message-ID: <6f1857b8-45db-4017-b6e8-02ecfa2104a3@redhat.com> Date: Thu, 11 Sep 2025 14:04:24 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [v5 03/15] mm/rmap: extend rmap and migration support device-private entries To: Balbir Singh , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: damon@lists.linux.dev, dri-devel@lists.freedesktop.org, Andrew Morton , Zi Yan , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Oscar Salvador , Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , Ralph Campbell , =?UTF-8?Q?Mika_Penttil=C3=A4?= , Matthew Brost , Francois Dugast References: <20250908000448.180088-1-balbirs@nvidia.com> <20250908000448.180088-4-balbirs@nvidia.com> From: David Hildenbrand Content-Language: en-US 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: <20250908000448.180088-4-balbirs@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 08.09.25 02:04, Balbir Singh wrote: subject: "mm/rmap: rmap and migration support for device-private PMD entries" > Add device-private THP support to reverse mapping infrastructure, > enabling proper handling during migration and walk operations. > > The key changes are: > - add_migration_pmd()/remove_migration_pmd(): Handle device-private > entries during folio migration and splitting > - page_vma_mapped_walk(): Recognize device-private THP entries during > VMA traversal operations > > This change supports folio splitting and migration operations on > device-private entries. > > Cc: Andrew Morton > Cc: David Hildenbrand > Cc: Zi Yan > Cc: Joshua Hahn > Cc: Rakie Kim > Cc: Byungchul Park > Cc: Gregory Price > Cc: Ying Huang > Cc: Alistair Popple > Cc: Oscar Salvador > Cc: Lorenzo Stoakes > Cc: Baolin Wang > Cc: "Liam R. Howlett" > Cc: Nico Pache > Cc: Ryan Roberts > Cc: Dev Jain > Cc: Barry Song > Cc: Lyude Paul > Cc: Danilo Krummrich > Cc: David Airlie > Cc: Simona Vetter > Cc: Ralph Campbell > Cc: Mika Penttilä > Cc: Matthew Brost > Cc: Francois Dugast > > Signed-off-by: Balbir Singh > --- [...] > +++ b/mm/page_vma_mapped.c > @@ -250,12 +250,11 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) > pvmw->ptl = pmd_lock(mm, pvmw->pmd); > pmde = *pvmw->pmd; > if (!pmd_present(pmde)) { > - swp_entry_t entry; > + swp_entry_t entry = pmd_to_swp_entry(pmde); > > if (!thp_migration_supported() || > !(pvmw->flags & PVMW_MIGRATION)) > return not_found(pvmw); > - entry = pmd_to_swp_entry(pmde); > if (!is_migration_entry(entry) || > !check_pmd(swp_offset_pfn(entry), pvmw)) > return not_found(pvmw); Why this change? Looks unrelated. > @@ -277,6 +276,15 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) > * cannot return prematurely, while zap_huge_pmd() has > * cleared *pmd but not decremented compound_mapcount(). Reminder to self: cleanup compound_mapcount() leftovers > */ > + swp_entry_t entry; > + > + entry = pmd_to_swp_entry(pmde); swp_entry_t entry = pmd_to_swp_entry(pmde); > + > + if (is_device_private_entry(entry)) { > + pvmw->ptl = pmd_lock(mm, pvmw->pmd); > + return true; > + } > + > if ((pvmw->flags & PVMW_SYNC) && > thp_vma_suitable_order(vma, pvmw->address, > PMD_ORDER) && > diff --git a/mm/rmap.c b/mm/rmap.c > index 236ceff5b276..6de1baf7a4f1 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1063,8 +1063,10 @@ static int page_vma_mkclean_one(struct page_vma_mapped_walk *pvmw) > } else { > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > pmd_t *pmd = pvmw->pmd; > - pmd_t entry; > + pmd_t entry = pmdp_get(pmd); > > + if (!pmd_present(entry)) > + continue; > if (!pmd_dirty(*pmd) && !pmd_write(*pmd)) > continue; > If you just did a pmdp_get() you should use it in these functions as well. If not (cleanup later), do a straight *pmd like the others. Apart from that nothing jumped at me. -- Cheers David / dhildenb