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[2003:d8:2f1d:ed00:1769:dd7c:7208:eb33]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4562e7f2e76sm20950955e9.5.2025.07.16.06.16.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 16 Jul 2025 06:16:50 -0700 (PDT) Message-ID: <914ce985-f642-473e-a312-0a390ab5e78b@redhat.com> Date: Wed, 16 Jul 2025 15:16:49 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" To: wang lian , akpm@linux-foundation.org, broonie@kernel.org, lorenzo.stoakes@oracle.com, sj@kernel.org, ziy@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: brauner@kernel.org, jannh@google.com, Liam.Howlett@oracle.com, shuah@kernel.org, vbabka@suse.cz, ludovico.zy.wu@gmail.com, gkwang@linx-info.com, p1ucky0923@gmail.com, ryncsn@gmail.com, zijing.zhang@proton.me References: <20250716123126.3851-1-lianux.mm@gmail.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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmgsLPQFCRvGjuMACgkQTd4Q 9wD/g1o0bxAAqYC7gTyGj5rZwvy1VesF6YoQncH0yI79lvXUYOX+Nngko4v4dTlOQvrd/vhb 02e9FtpA1CxgwdgIPFKIuXvdSyXAp0xXuIuRPQYbgNriQFkaBlHe9mSf8O09J3SCVa/5ezKM OLW/OONSV/Fr2VI1wxAYj3/Rb+U6rpzqIQ3Uh/5Rjmla6pTl7Z9/o1zKlVOX1SxVGSrlXhqt kwdbjdj/csSzoAbUF/duDuhyEl11/xStm/lBMzVuf3ZhV5SSgLAflLBo4l6mR5RolpPv5wad GpYS/hm7HsmEA0PBAPNb5DvZQ7vNaX23FlgylSXyv72UVsObHsu6pT4sfoxvJ5nJxvzGi69U s1uryvlAfS6E+D5ULrV35taTwSpcBAh0/RqRbV0mTc57vvAoXofBDcs3Z30IReFS34QSpjvl Hxbe7itHGuuhEVM1qmq2U72ezOQ7MzADbwCtn+yGeISQqeFn9QMAZVAkXsc9Wp0SW/WQKb76 FkSRalBZcc2vXM0VqhFVzTb6iNqYXqVKyuPKwhBunhTt6XnIfhpRgqveCPNIasSX05VQR6/a OBHZX3seTikp7A1z9iZIsdtJxB88dGkpeMj6qJ5RLzUsPUVPodEcz1B5aTEbYK6428H8MeLq NFPwmknOlDzQNC6RND8Ez7YEhzqvw7263MojcmmPcLelYbfOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaCwtJQUJG8aPFAAKCRBN3hD3AP+DWlDnD/4k2TW+HyOOOePVm23F5HOhNNd7nNv3 Vq2cLcW1DteHUdxMO0X+zqrKDHI5hgnE/E2QH9jyV8mB8l/ndElobciaJcbl1cM43vVzPIWn 01vW62oxUNtEvzLLxGLPTrnMxWdZgxr7ACCWKUnMGE2E8eca0cT2pnIJoQRz242xqe/nYxBB /BAK+dsxHIfcQzl88G83oaO7vb7s/cWMYRKOg+WIgp0MJ8DO2IU5JmUtyJB+V3YzzM4cMic3 bNn8nHjTWw/9+QQ5vg3TXHZ5XMu9mtfw2La3bHJ6AybL0DvEkdGxk6YHqJVEukciLMWDWqQQ RtbBhqcprgUxipNvdn9KwNpGciM+hNtM9kf9gt0fjv79l/FiSw6KbCPX9b636GzgNy0Ev2UV m00EtcpRXXMlEpbP4V947ufWVK2Mz7RFUfU4+ETDd1scMQDHzrXItryHLZWhopPI4Z+ps0rB CQHfSpl+wG4XbJJu1D8/Ww3FsO42TMFrNr2/cmqwuUZ0a0uxrpkNYrsGjkEu7a+9MheyTzcm vyU2knz5/stkTN2LKz5REqOe24oRnypjpAfaoxRYXs+F8wml519InWlwCra49IUSxD1hXPxO WBe5lqcozu9LpNDH/brVSzHCSb7vjNGvvSVESDuoiHK8gNlf0v+epy5WYd7CGAgODPvDShGN g3eXuA== Organization: Red Hat In-Reply-To: <20250716123126.3851-1-lianux.mm@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: VOy8sgtl9_ehZNGwbWsXmEbNxsyxWsHUdDdLZHZM3bg_1752671812 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: grs8pn41p1egf6o6j55txgoesz9791z1 X-Rspam-User: X-Rspamd-Queue-Id: 01B8F4000A X-Rspamd-Server: rspam02 X-HE-Tag: 1752671818-421277 X-HE-Meta: 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 E/OLz7ID 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 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 16.07.25 14:31, wang lian wrote: > Several mm selftests use the `asm volatile("" : "+r" (variable));` > construct to force a read of a variable, preventing the compiler from > optimizing away the memory access. This idiom is cryptic and duplicated > across multiple test files. > > Following a suggestion from David[1], this patch refactors this > common pattern into a FORCE_READ() macro > > [1] https://lore.kernel.org/lkml/4a3e0759-caa1-4cfa-bc3f-402593f1eee3@redhat.com/ > > Signed-off-by: wang lian > Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand -- Cheers, David / dhildenb