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[58.152.75.21]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35a02fc9454sm7295623a91.12.2026.03.12.20.39.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Mar 2026 20:39:46 -0700 (PDT) Message-ID: <06535c30-ce87-43b2-9670-53e56ca04c3c@gmail.com> Date: Fri, 13 Mar 2026 11:39:41 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/mempolicy: add sysfs interface to override NUMA node bandwidth To: Joshua Hahn Cc: akpm@linux-foundation.org, david@kernel.org, dan.j.williams@intel.com, ying.huang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jonathan.Cameron@huawei.com, linux-cxl@vger.kernel.org, dave.jiang@intel.com, gourry@gourry.next References: <20260312150022.1373486-1-joshua.hahnjy@gmail.com> Content-Language: en-US From: Yee Li In-Reply-To: <20260312150022.1373486-1-joshua.hahnjy@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Joshua, Thanks for your feedback and kind wishes. > I just wanted to touch on this. Is this true? Weighted interleave already > exposes sysfs that lets the user set the weights they want. On one hand > I think it would be helpful for there to be a tool to see what the > effects of setting bandwidth information on a system could be, if it > had other side effects. I'm not sure if there is a strong case to do this > purely for weighted interleave auto-tuning, which already has a manual > weight override and pretty simple calculations : -) I agree — writing a small userspace tool to compute the weights based on actual measured bandwidths (from mlc or stream) is a really good approach. > Thank you for the helpful clarification. Just to be sure, are there > other intended things that the user can test other than what weights > weighted interleave would resolve to? We can continue DRAM + CXL weighted interleave performance testing later, following Gregory Price's experiments [1]. [1] Link: https://lore.kernel.org/linux-mm/20240103224209.2541-1-gregory.price@memverge.com/