From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f66.google.com (mail-qv1-f66.google.com [209.85.219.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7472333729 for ; Tue, 24 Feb 2026 20:04:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771963451; cv=none; b=mbROwseRF8V9j1cn3lKosZbBAzzfQvBNbY3GvpGemcmYelJ1BTlWDMeF+XvnFeaOzCOFUydPm+dpA//XAQWb74CJaKP+N4Wf6EnUFTGSB/P0tGCpK5IluBr2p3poAbdFWe8zbVTbIYtldoqIIx9vS/d+Bb6wbcwHaemKC6HXkxc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771963451; c=relaxed/simple; bh=EY3X/GbQP1UHkBYA2aCjxbCF6E3NLDDOtQj5TdI+ycg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iS90zeDaL/6ehltMZFFMQ8IUQyIx2YKCNgo9/5S6hEtksc/w14lK+kwHp9kjOuVasP0O0kiAtU10ZvB7t0w2YodmepBHvNqFYl2d1lFDCoUGrhZvlCX99NwVuVLMbZ1i5JfVPBsrwYf6sth93O4BRSz6kbLScgEgL9c0zM9rpNE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cs.cmu.edu; spf=pass smtp.mailfrom=andrew.cmu.edu; dkim=pass (2048-bit key) header.d=cs.cmu.edu header.i=@cs.cmu.edu header.b=AUM2zdyw; arc=none smtp.client-ip=209.85.219.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=cs.cmu.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=andrew.cmu.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cs.cmu.edu header.i=@cs.cmu.edu header.b="AUM2zdyw" Received: by mail-qv1-f66.google.com with SMTP id 6a1803df08f44-899a9f445cbso12204986d6.0 for ; Tue, 24 Feb 2026 12:04:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.cmu.edu; s=google-2021; t=1771963447; x=1772568247; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=kez7XbtF2ZH1d8xoXH+eVokCW4VeclXLsEwDWocfZR8=; b=AUM2zdywz/Sf+8c1mr3ei/TqXanB0wVi6mkHQblhwEr0HgFsTGSe5S2VF/yM5aFMR/ 7qn2x1SXuGo8SBpVpVH8SmUDaTZieVVW0xDVcfVXMv4OqAq623URjY18Qf745nKAfUEz jquTridFN2m/zaTde7C6mk8oswnRGobtrBDb8xwfr7tLzDOZTM40TpFfs6lsn9PYV95l jYBSj64vRhZ9yF5VBmD1k5aUu6nr46EDAh9ao/iDLRtCiFpsWxM6yL44MKWBTMGfRZxk 5O+i18fuDSitWV5uxl2/1tkcStc72W2kWfsunbDAGpxL6Dx7l+aKwXgum49rzmO5Cmmm aHTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771963447; x=1772568247; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=kez7XbtF2ZH1d8xoXH+eVokCW4VeclXLsEwDWocfZR8=; b=hcGVNKlfK992/BDeV9bkSL/iKRLVi/EUW0/29ZB9WkrKwiWgh6/LdFCm+eb9gix27y knFNlc7ysjEx5PRN+3ohWvfxAvC1c12TdZjmfl+H2Uoq5RMB5sLkxBBB3jimtGPjPneU M3j9xOn4ZqJT6YzxHRNjrAY82dBegyHoVAIuYX3VEKsGvP+uHdqkYDasFG9/litto/Tj dI5kkRdZbTQ4h66PYyfHniQcgvFRe2rg65NNpCs5UA7OGGyCSDbRfBrRhd/4WESBtHQN OKkgX/OzMMc6F2c1l1qkrzmFZfSZCz28G1CWAUmJaL7UQOn7OuGj8G9jSaytWIVNxSR+ TN+g== X-Forwarded-Encrypted: i=1; AJvYcCWpEPNA8OUYEwHGBH7ZBb/F6No0dPkWD1cp6MMTZNfi8EhMxLtWCdqxFvCzXHhpkZK0hW8f0nRx@vger.kernel.org X-Gm-Message-State: AOJu0YwGeZnmHfsHywdVxRg8+yB1HjUM9BOFzOq8MERT9YIUEZxjutEW 9ma19w81JAq+mue+LB1Y/mdGjHP26hRBrR1zjBUc/yL22ec2YkZzqulKuMxP2ZeF7gJXdO3jF39 02fik8BG3YwEPeTXKWE9+vwoEuZZA/CP9zzgtadAtL3HtXi8MxG7Zu3cUfUJh3xjEB1Eq1qbtSo O2ZiFV+izWDRe84AonUGHmRwQw4YgJxGh5pNiGKg== X-Gm-Gg: ATEYQzyMaBVa9+UVtz2FGGKghP66Qn3DtKNhPdfC7Mxtkqk3ikCFh4JrYdFRr6J0SW0 L0YF8nkOHKdsy8my/9KNG9wGCmG/mmRTGPh/j1thhQgxJSGsXyBWDzsX1BuozcFl9LcrsktUNSg mX/J0ncbg497u/xrHzILgNaiaNfagxClzauwn4TKXNS+1qK/NOq9XrEhQ5/4P6j85p2U5D3bRO2 xs6oMcTsOSnGg/p8SJ4HhRwCWi9i1sNUWUiaj5iRfr067F+DD10sywBZ1rq3jEsGunW0p5NGTOz JoHAGZu3D2NoR7wpggLN61+mtj12qj4KqWbg0cKHTciNSl/rS48zVOHlsQIB4cVpFLIzym+C7fs S8wz8WCQMRMH/q8NlQ/utN3B2Vpwvte5jDNrYZFK+zaCTseTPl6mx15vbQJx+C49rCIn4pKAU48 GTWA+Z5fUqe38Vx9AZNrUCFDMqzVq4YWy9mgEOfZ6rFPkWb5NW4d+97c3RhL+ibbOoDZ9x1p0Cd diVnE7W X-Received: by 2002:a05:6214:194d:b0:895:4852:ef55 with SMTP id 6a1803df08f44-89979d3b10emr224487636d6.33.1771963446716; Tue, 24 Feb 2026 12:04:06 -0800 (PST) Received: from localhost.localhost (pool-74-98-231-160.pitbpa.fios.verizon.net. [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: cgroups@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