From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 124014A21 for ; Sat, 15 Nov 2025 00:51:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763167909; cv=none; b=FpFYWgnENIvKb5qw75yQMS64cxHN80ayfNzpKNVqEYCntOa3Ib7vIYY+/AW5UIPbhaI79Pa9/6vIeX7k5LJYzchLGiTgpGvvahHy2E0IgiPJX83/s3JhLDqiQV/PQGYgksCtiWqxtAVb/3zVrmoy9Qbgzsoe5QwAETRPmBMyfKA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763167909; c=relaxed/simple; bh=c34bXnZOMXHB1/otiiYKeqjSsUyBsx3eTgV6OQSOEQ0=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=EJyTX0YkQ7TewZdbvQeqGTrgSYFLg7NfRq4t1j0JBK0h1xDd0UzEGUBBZ9NPGVmcvFgRiJO6zHpvoYN9OxJnX1Nsoa+7vIodmzHJyBFdJZWmuPqczX2xY2NfPxF7Ceeq5KtwQGWVe1nj9j9HoTI7kPruQorbgJw+rtbyHSL+VHg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Yr5VhBnK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Yr5VhBnK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACB6CC4CEF1; Sat, 15 Nov 2025 00:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1763167908; bh=c34bXnZOMXHB1/otiiYKeqjSsUyBsx3eTgV6OQSOEQ0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Yr5VhBnKAuzj9cC+8XdpDTsNmuHxB6kbc7gGiLO0L9h/IvJnsYCzBILmm3BDLjQh3 JgU3YmTjZ48ntDuyp2AVorPbLdrmM1POS7rvsWOIFtsRM0MCNuApKBdMCuLns/6tpS dCWkfu6Fa+z0adCrzQgoXMqGsYM3IW5H52Q76bM0= Date: Fri, 14 Nov 2025 16:51:46 -0800 From: Andrew Morton To: Balbir Singh Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org, David Hildenbrand , 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 , Mika =?ISO-8859-1?Q?Penttil=E4?= , Matthew Brost , Francois Dugast Subject: Re: [PATCH] fixup: mm/rmap: extend rmap and migration support device-private entries Message-Id: <20251114165146.5c51eeeee200bd37b378bd45@linux-foundation.org> In-Reply-To: <20251115002835.3515194-1-balbirs@nvidia.com> References: <20251115002835.3515194-1-balbirs@nvidia.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 15 Nov 2025 11:28:35 +1100 Balbir Singh wrote: > Follow the pattern used in remove_migration_pte() in > remove_migration_pmd(). Process the migration entries and if the entry > type is device private, override the pmde with a device private entry > and set the soft dirty and uffd_wp bits with the pmd_swp_mksoft_dirty > and pmd_swp_mkuffd_wp > > ... > > This fixup should be squashed into the patch "mm/rmap: extend rmap and > migration support" of mm/mm-unstable > OK. After fixing up mm-replace-pmd_to_swp_entry-with-softleaf_from_pmd.patch, mm.git's mm/huge_memory.c has the below. Please double-check. void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) { struct folio *folio = page_folio(new); struct vm_area_struct *vma = pvmw->vma; struct mm_struct *mm = vma->vm_mm; unsigned long address = pvmw->address; unsigned long haddr = address & HPAGE_PMD_MASK; pmd_t pmde; softleaf_t entry; if (!(pvmw->pmd && !pvmw->pte)) return; entry = softleaf_from_pmd(*pvmw->pmd); folio_get(folio); pmde = folio_mk_pmd(folio, READ_ONCE(vma->vm_page_prot)); if (pmd_swp_soft_dirty(*pvmw->pmd)) pmde = pmd_mksoft_dirty(pmde); if (softleaf_is_migration_write(entry)) pmde = pmd_mkwrite(pmde, vma); if (pmd_swp_uffd_wp(*pvmw->pmd)) pmde = pmd_mkuffd_wp(pmde); if (!softleaf_is_migration_young(entry)) pmde = pmd_mkold(pmde); /* NOTE: this may contain setting soft-dirty on some archs */ if (folio_test_dirty(folio) && softleaf_is_migration_dirty(entry)) pmde = pmd_mkdirty(pmde); if (folio_is_device_private(folio)) { swp_entry_t entry; if (pmd_write(pmde)) entry = make_writable_device_private_entry( page_to_pfn(new)); else entry = make_readable_device_private_entry( page_to_pfn(new)); pmde = swp_entry_to_pmd(entry); if (pmd_swp_soft_dirty(*pvmw->pmd)) pmde = pmd_swp_mksoft_dirty(pmde); if (pmd_swp_uffd_wp(*pvmw->pmd)) pmde = pmd_swp_mkuffd_wp(pmde); } if (folio_test_anon(folio)) { rmap_t rmap_flags = RMAP_NONE; if (!softleaf_is_migration_read(entry)) rmap_flags |= RMAP_EXCLUSIVE; folio_add_anon_rmap_pmd(folio, new, vma, haddr, rmap_flags); } else { folio_add_file_rmap_pmd(folio, new, vma); } VM_BUG_ON(pmd_write(pmde) && folio_test_anon(folio) && !PageAnonExclusive(new)); set_pmd_at(mm, haddr, pvmw->pmd, pmde); /* No need to invalidate - it was non-present before */ update_mmu_cache_pmd(vma, address, pvmw->pmd); trace_remove_migration_pmd(address, pmd_val(pmde)); }