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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488ee038752sm117771055e9.9.2026.04.15.02.16.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Apr 2026 02:16:25 -0700 (PDT) Date: Wed, 15 Apr 2026 10:16:23 +0100 From: David Laight To: Dev Jain Cc: "David Hildenbrand (Arm)" , 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 Subject: Re: [PATCH v2] selftests/mm: Simplify byte pattern checking in mremap_test Message-ID: <20260415101623.33004858@pumpkin> In-Reply-To: <57b5d0f9-3e56-4f96-9e3a-2f475a78a8eb@arm.com> References: <20260415044509.579428-1-dev.jain@arm.com> <2e34b619-085f-4a9c-bb41-bc024fd40dd7@kernel.org> <57b5d0f9-3e56-4f96-9e3a-2f475a78a8eb@arm.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) 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 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. > > d) Just always verify the whole regions. Without the rand() magic this > > will probably be just ... fairly fast? > > Yeah we are doing a simple memcmp() so it is fine. You don't need a copy of the buffer, just compare against the pattern that filled it. David > > I'll implement these changes. > > > > >