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Howlett" , Andrew Morton , Vlastimil Babka , Mike Rapoport , Michal Hocko , Matthew Wilcox Cc: iommu@lists.linux.dev, security@kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen References: <20251014130437.1090448-1-baolu.lu@linux.intel.com> <20251014130437.1090448-4-baolu.lu@linux.intel.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: <20251014130437.1090448-4-baolu.lu@linux.intel.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: nX29wlFhw1hU2fW7nkLJ1p7zvXTPlnl4cGvZ8gqYOp0_1760643226 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 11D00C000D X-Rspamd-Server: rspam03 X-Stat-Signature: g4rqhi9xzro33aqpbtoj4xfugx3bhp5z X-HE-Tag: 1760643230-44105 X-HE-Meta: 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 9SXdfi/k 7pEl8WMkdBHotMjkoVhBereD9XMymYC61HJIJFs2JHdZWlrE= 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 14.10.25 15:04, Lu Baolu wrote: > From: Dave Hansen > > There are a billion ways to refer to a physical memory address. > One of the x86 PMD freeing code location chooses to use a 'pte_t *' to > point to a PMD page and then call a PTE-specific freeing function for > it. That's a bit wonky. > > Just use a 'struct ptdesc *' instead. Its entire purpose is to refer > to page table pages. It also means being able to remove an explicit > cast. > > Right now, pte_free_kernel() is a one-liner that calls > pagetable_dtor_free(). Effectively, all this patch does is > remove one superfluous __pa(__va(paddr)) conversion and then > call pagetable_dtor_free() directly instead of through a helper. > > Signed-off-by: Dave Hansen > Signed-off-by: Lu Baolu > Reviewed-by: Jason Gunthorpe > Reviewed-by: Kevin Tian > --- > include/linux/mm.h | 6 ++++-- > arch/x86/mm/pgtable.c | 12 ++++++------ > 2 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 15ce0c415d36..94e2ec6c5685 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3203,8 +3203,7 @@ pte_t *pte_offset_map_rw_nolock(struct mm_struct *mm, pmd_t *pmd, > ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd))? \ > NULL: pte_offset_kernel(pmd, address)) > > -#if defined(CONFIG_SPLIT_PMD_PTLOCKS) > - > +#if defined(CONFIG_SPLIT_PMD_PTLOCKS) || defined(CONFIG_X86_64) Yeah, that is weird. I'd have thought we can simply move this out of the ifdef? The CONFIG_X86_64 stuff certainly has to go one way or the other. As PTE tables always fit in a single page, pgtable_page(pte) is sufficient. PMD tables can exceed a single page on some archs, so we have to find the first page first that we can then cast. Can't immediately see why that causes compile issues. > static inline struct page *pmd_pgtable_page(pmd_t *pmd) > { > unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); > @@ -3215,6 +3214,9 @@ static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd) > { > return page_ptdesc(pmd_pgtable_page(pmd)); > } > +#endif -- Cheers David / dhildenb