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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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: ED426C0007 X-Stat-Signature: wixep6gfsoawuq9kufau7wpcmr3wi4is X-HE-Tag: 1771963447-955435 X-HE-Meta: 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 8nKASGLr 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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