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[74.98.231.160]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-899b3863159sm7696406d6.24.2026.02.24.12.04.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Feb 2026 12:04:06 -0800 (PST) Date: Tue, 24 Feb 2026 20:03:59 +0000 From: Kaiyang Zhao To: Gregory Price Cc: Joshua Hahn , Michal Hocko , Johannes Weiner , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Roman Gushchin , Shakeel Butt , Muchun Song , Waiman Long , Chen Ridong , Tejun Heo , Michal Koutny , Axel Rasmussen , Yuanchu Xie , Wei Xu , Qi Zheng , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [RFC PATCH 0/6] mm/memcontrol: Make memcg limits tier-aware Message-ID: References: <20260224161357.2622501-1-joshua.hahnjy@gmail.com> 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-Disposition: inline In-Reply-To: On Tue, Feb 24, 2026 at 01:49:21PM -0500, Gregory Price wrote: > > > > > > Is this typical in real life configurations? > > > > I would say so. I think that the two examples above are realistic > > scenarios that cloud providers and hyperscalers might face on tiered systems. > > > > The answer is unequivocally yes. > > Lacking tier-awareness is actually a huge blocker for deploying mixed > workloads on large, dense memory systems with multiple tiers (2+). Hello! I'm the author of the RFC in 2024. Just want to add that we've recently released a preprint paper on arXiv that includes case studies with a few of Meta's production workloads using a prototype version of the patches. The results confirmed that co-colocated workloads can have working set sizes exceeding the limited top-tier memory capacity given today's server memory shapes and workload stacking settings, causing contention of top-tier memory. Workloads see significant variations in tail latency and throughput depending on the share of top-tier tier memory they get, which this patch set will alleviate. Best, Kaiyang [1] https://arxiv.org/pdf/2602.08800