From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 374F3457E55; Fri, 11 Sep 2026 17:10:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789146618; cv=none; b=p356PQGYvqEam5Lp4u7QHZpZ8y0sQBa2RKPBgTddGbdwsr6zGmX73LhyaHT/KoKQ8nnIOiEaFobu3ebdrDoUwd8JvXM5edGAN/QqtWa0DX4sYRKpE8nMmARxNV1z8MBs7atSAudqF7S1VgxxxucBGOonA3hvIWpq2PGyGrA8TRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789146618; c=relaxed/simple; bh=70mmmfYxx5aDBfb3A3A64dexxI6qP8wxu39hdOEJ1aE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BvwgrWqQjO0e00cuX07PdfLVFgq5LyjZDm+9ETeFwbRDJ+PvEQ5xx1+Kqe9aEh99Rtj4kncKTcrCsSDVDSyCxdpEOhH/XAfkfa27mW/raBpEX4GVFEG4r3ld+RwVZUGPE22VqIQLiffkNwQHhoJKu34nbI3LoQta0GkE6BUBSIg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ijM28yeS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ijM28yeS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF04C1F00893; Fri, 11 Sep 2026 17:10:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789146616; bh=s9/6KbXsN5PKvzZs2esn/AhPtSfdFVVRLNXzVuGAieA=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ijM28yeSeyX61csI7of/aYV6Iu23+fQwE2+XMHuORDOd9Q58+YKhljzXl+IBz4Fum GTMuOS39dD0b/3zG27EdOqjAkusXj6vqwIKDQom13aNYWLtWjARY8yD4Fc6x0WSfAd 5HAYNkwusAIKERa3WHgLnp9dbK4wyC6PAL6LjnODK0XIQGto7t/yd8GJT72smbQhyu OzZ3q1/AtOHdfG+oKc4RjaNN9Ctxu4fwIB3/CiLYKdFCtFfw3NRb+woAMvc191s+Fq 6WOJgh4F2SXLfO/k1FpUXsN9xExTqEQkHaoouynhFq/HctD3ifs1J/7Tb6gKYO0V6p uNN1MzB53btqw== Message-ID: <0a4fd9e1-3e7d-4910-99ee-6f6f89b5ca93@kernel.org> Date: Fri, 11 Sep 2026 19:09:41 +0200 Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/8] mm: use hw_pte_t for generic PTE table storage To: Muhammad Usama Anjum , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Dimitri Sivanich , Arnd Bergmann , Greg Kroah-Hartman , "James E.J. Bottomley" , Helge Deller , Juergen Gross , Stefano Stabellini , Muchun Song , Oscar Salvador , Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Andrey Ryabinin , Pasha Tatashin , Chris Li , Kairui Song , Uladzislau Rezki , Steven Rostedt , Masami Hiramatsu , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , SJ Park , "Matthew Wilcox (Oracle)" , Jan Kara , Jason Gunthorpe , Leon Romanovsky , Miaohe Lin , Dennis Zhou , Tejun Heo , Christoph Lameter , Mike Rapoport , Johannes Weiner , ziy@nvidia.com, pfalcato@suse.de, agordeev@linux.ibm.com, ryan.roberts@arm.com Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, damon@lists.linux.dev References: <20260903103002.1091859-1-usama.anjum@arm.com> <20260903103002.1091859-4-usama.anjum@arm.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: <20260903103002.1091859-4-usama.anjum@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/3/26 12:29, Muhammad Usama Anjum wrote: > Generic page-table interfaces use pte_t * for both pointers to PTE table > storage and pointers to software PTE values. Convert the generic > declarations and their MM, fs, and kernel users together so parameters, > return types, callbacks, and local pointers that designate table storage > use hw_pte_t *. > > Include linux/pgtable_types.h from headers that expose the converted > interfaces. It continues to provide pgprot_t to vmalloc.h through > asm/page.h. > > Keep software PTE values as pte_t and retain pte_t * for value interfaces. > > No architecture selects ARCH_HAS_HW_PTE_T at this point, so hw_pte_t > remains an alias of pte_t and this changes the interface vocabulary without > changing representation or behavior. > > Most of this mechanical conversion was generated with the Coccinelle script > included in the cover letter. The script deliberately ignores pte_t * > pointers named ptentp because they designate software PTE values. The > result was then audited, and sites the script could not convert were > updated by hand. > > Signed-off-by: Muhammad Usama Anjum > --- > Changes since v1: > - Fold the header includes into their first user instead of keeping a > stand-alone preparation patch. > - Rebase onto mm-new and rerun the Coccinelle script. > - Use software PTE value terminology. > > Changes since RFC v1: > - Clarify that linux/pgtable_types.h provides both generic hw_pte_t > definitions. > - Clarify that the distinct generic definition is activated by an > architecture opt-in. > --- > fs/hugetlbfs/inode.c | 3 +- > fs/proc/task_mmu.c | 33 ++++++------- > include/asm-generic/hugetlb.h | 15 +++--- > include/asm-generic/pgalloc.h | 6 +-- > include/asm-generic/tlb.h | 5 +- > include/linux/hugetlb.h | 50 +++++++++++--------- > include/linux/mm.h | 26 +++++------ > include/linux/page_table_check.h | 10 ++-- > include/linux/pagewalk.h | 8 ++-- > include/linux/pgtable.h | 79 +++++++++++++++++--------------- > include/linux/rmap.h | 2 +- > include/linux/swapops.h | 6 ++- > include/linux/vmalloc.h | 4 +- > include/trace/events/xen.h | 10 ++-- > kernel/bpf/arena.c | 9 ++-- > kernel/events/core.c | 3 +- > mm/damon/ops-common.c | 2 +- > mm/damon/ops-common.h | 2 +- > mm/damon/vaddr.c | 20 ++++---- > mm/debug_vm_pgtable.c | 2 +- > mm/filemap.c | 4 +- > mm/gup.c | 9 ++-- > mm/highmem.c | 15 +++--- > mm/hmm.c | 6 +-- > mm/huge_memory.c | 4 +- > mm/hugetlb.c | 60 ++++++++++++------------ > mm/hugetlb_vmemmap.c | 13 +++--- > mm/internal.h | 16 +++---- > mm/kasan/init.c | 12 ++--- > mm/kasan/shadow.c | 6 +-- > mm/khugepaged.c | 50 ++++++++++++-------- > mm/ksm.c | 7 +-- > mm/madvise.c | 14 +++--- > mm/mapping_dirty_helpers.c | 4 +- > mm/memory-failure.c | 6 +-- > mm/memory.c | 78 ++++++++++++++++--------------- > mm/mempolicy.c | 4 +- > mm/migrate.c | 4 +- > mm/migrate_device.c | 4 +- > mm/mincore.c | 4 +- > mm/mlock.c | 4 +- > mm/mprotect.c | 19 ++++---- > mm/mremap.c | 4 +- > mm/page_table_check.c | 4 +- > mm/pagewalk.c | 9 ++-- > mm/percpu.c | 2 +- > mm/pgtable-generic.c | 20 ++++---- > mm/ptdump.c | 2 +- > mm/rmap.c | 6 +-- > mm/sparse-vmemmap.c | 22 ++++----- > mm/swap_state.c | 3 +- > mm/swapfile.c | 5 +- > mm/userfaultfd.c | 32 +++++++------ > mm/util.c | 2 +- > mm/vmalloc.c | 11 +++-- > mm/vmscan.c | 6 +-- > 56 files changed, 410 insertions(+), 356 deletions(-) > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index 7611a8470ea26..ddaab714c3e02 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -328,7 +328,8 @@ static void hugetlb_delete_from_page_cache(struct folio *folio) > static bool hugetlb_vma_maps_pfn(struct vm_area_struct *vma, > unsigned long addr, unsigned long pfn) > { > - pte_t *ptep, pte; > + hw_pte_t *ptep; > + pte_t pte; > > ptep = hugetlb_walk(vma, addr, huge_page_size(hstate_vma(vma))); > if (!ptep) This is interesting. Assuming we'd had a hugetlb_hw_pte_t, we be able tojust naturally catch things like using ptep_get() instead of huge_ptep_get() That caused bugs and headakes before. But I'm not actually proposing that at this point, because it would make messed up infrastructure where we hacked in hugetlb, like page_vma_mapped_walk() harder to use. Regarding this patch, I guess we'll regenerate it when the time comes. We *might* have to do this stepwise. E.g., merge patch #1 first, to then convert individual MM components. But we can discuss that once the time comes. -- Cheers, David