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b=kQSTaEVnmcNMEayJC4Cdj/51l1D+CotiU8oJhSCZ+n+XCW38zrM7FFjnFodrNTAo0 hoXYF0jODMNUIA5dGlfQrWI1w1Sb4EWPDWx+EiNqzha5OdImJSeXsRWy1PHze80tx1 ij14qPLStE8IcUj0K+1WYPLdnV6DQHiTBLuVsh/H/qRUHMFcVW4gZRZiDxyVGQCr+B zNt0tqwNFsWFE23NVYbPp8mTWU2Jy0N/grW2QJ5Xm4Rtz5yVpPrzYRQ2EI+YO5ro4d DroTFqaFWxiwoXl1CRfNxO86ExUf9CGrwI+9shWaafAXbSIjZ5fIl9/a2iZO2Ru5YC kyaaVfKV2GD6Q== Message-ID: <6339e1fe-bdd0-4ae1-bab8-5a2ead0e6a84@kernel.org> Date: Wed, 15 Apr 2026 11:21:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] selftests/mm: Simplify byte pattern checking in mremap_test To: David Laight , Dev Jain Cc: akpm@linux-foundation.org, shuah@kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, Sarthak Sharma References: <20260415044509.579428-1-dev.jain@arm.com> <2e34b619-085f-4a9c-bb41-bc024fd40dd7@kernel.org> <57b5d0f9-3e56-4f96-9e3a-2f475a78a8eb@arm.com> <20260415101623.33004858@pumpkin> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 996F980002 X-Stat-Signature: gbpiqm6gdnesiqoh5ff8iudmss8agane X-Rspam-User: X-HE-Tag: 1776244908-765984 X-HE-Meta: U2FsdGVkX1+hKHYZfXwrmb+DQXcZ6RId2V4WjP27sJoaLA5CL9VTDNH1y/hEnynnlvHJiqJp1pkqCjqazRf5NwYinYAaQaAX3hY0jwV7lZnoVUcoF/hj1kvPIPrS4qm74ItcVuy+xcGth1bb40syS0KB+EO+dH65tP0LbhoCfA/xXxrB94wpvNm1fCRGnpv6lZZsRCGGPHEwc+sfrLZwB3AXgIVSQ5Jq0+LJFVjT8oERmAHJ6SZedd6JY5OKqnsGm3dRgngEKoeIgx6DpHFjnnQ/IaT69No3DlZGH/Sme3PGfUZ9Wfz1j2U06gw79ep9P3GPwNlROs0b4hr9eXYgNu2dbhup7z8rP9XFFfMzkpywVdunfKPLggIp8IgFEh0f/Rmq1l1Zd3oZEKGqhjZAUaPiFRq9iWNU14ZlRTiUMNnWvYvTovnOFi76qo+SbGCClimG0z3qz+I5vHkL5A+Ar6E1aii3e/dqNQEAZ0ABz8fpdJ4dt5U7UGXi/ThJ120Vu634GT6VsHEw6qIhTFW8TCFPZXP+L9sAA8rYTYQQudHPq7V0ObG8sYfzYUax7weoso9m9jKgziwqA53eahaz3lfpaEnbJULaVfQMlqeuRA+i3ZzeKI1e91v1uA+fprXC+kwPV8s5jg3XOyzNXzk6V2xiVsLbXI61gQrTHO1W/KeOaop4LDIqldesR2Jac7vgsRAC5KydTcuk9hyt2IW9OgpvdYSPPgx2VoTYKArMN0Bn9+ivhUHl+JfQn+5Hc1akv7/6gsfUuTsvouP/irjAKRvF45iuzYi5Ymzb+GwD5wK4KpG8UsZa1c7w0mPiPnugX5R1PWn+/MM2ik3K3s/Kl1ss9+GK60iqyuAoBo2Ns9wLMejoJm5PrfQfeQKVFqEyVCoNcWiSw9NoQCxlsr88skKWh7gGcFpeMtq2ilAvOSWEohi6Um+RUnAXpSNgTXCiR0+uARxHzwyeUa+PpB3 FfW1sj10 k9bJhwfOf9G8XAwz4nCQLDcUTr5EgsYejR0iTKPVsvHaOnNZ1zeVLuGwj3SDkEdbqypenoYhkvK95NKBQPokvPxgh/I53nmW3h4WuLHlGUqUBQoX9gpmoKiEg/UfW7uym7t697HwvoEQQsCIJvoMSSCQihCuVOwBrhK7A4ruM0N9GAHLuiIzx1yZpGfrPL/vMgUFR+L9bGOuVeiyQMfqJQfGaLysvb+KdwtPTqSBXysK66UmCQTxdfC3QAFlRQMU5Wm6jaWrjtYfj1M2aOB5IsRAPUY+AbmU5/VQZBgrnm9ppp3m9o9pi8EZZm0dxAFKhej+Vd8VNSth4kL6f2BpQO7S+MFWU7LP1bzWWLgI+VH1nPdtrgNY/FcX4v5pJu2F/GpX2FOK9LRh2N5U9vYsiCp+CYW/Wk4+cxrYTIaM8kAAvJovCTciO5m3lnrS5i98CnB9VFIr8e0P/BY7Ec0BAob+fsg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/15/26 11:16, David Laight wrote: > On Wed, 15 Apr 2026 14:05:01 +0530 > Dev Jain wrote: > > ... >>> >>> c) Remove any randomization from the test. There is no need for random >>> patterns, just fill pages with increasing numbers. >> >> Agreed. > > I'd start from (say) 0x123456789abcdef0 rather than zero to avoid lots > of zero bytes. I'd just initialize the first page with (unsigned int) 0's, the second page with (unsigned int) 1's etc. mremap only moved full pages, so it would even be sufficient to only check the first (unsigned int) in a page. But obviously, just comparing full pages might be easier. -- Cheers, David