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[209.85.220.41]) by mx.google.com with SMTPS id 139sor7001096ywg.99.2019.04.23.08.30.58 for (Google Transport Security); Tue, 23 Apr 2019 08:30:58 -0700 (PDT) Received-SPF: pass (google.com: domain of shakeelb@google.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=jaJ2fkwH; spf=pass (google.com: domain of shakeelb@google.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=yEsJunfUbaZmio+edIZHR7uNumWd1MHNzVqBngWscks=; b=jaJ2fkwH1mCx0hopdYwEXAa6YwETI3xUruPfHlDIT+EBBuYIC7jKH+kYeGmrn3J0KV 0K7M7FOYTg7yEL+VytFmj7npBJvQVcXJXUk13yMyhXSUboKKBm03V0l4JPmtghQDeyWH kPp9DTwV6sGINI/qX5HziGPtLxUwsW/HYNElIgtCt5vj6r1G7posqTw+8/D5wI2lapP5 8rdrGSuFUoL1oVf1K7qxdM39NhmrUB5RQtwAOyJDqAXxH7Y1jtozkhQVS/JrNttthJLR YiUjQalCCpRyXkjbgBWGPXqWVvB7FyDUhFt2ts1+3hiwB+swCoz/xlMAf52ZaBJiWXw3 LnTw== X-Google-Smtp-Source: APXvYqznU3B5y7vUTJV9lSTCzlHB67tsYye4b9R5i29Jr3eQ7gJOeRnV8BkHalFoUNQz4NeVqVqTcHq6UOv9tX23lrs= X-Received: by 2002:a81:2204:: with SMTP id i4mr21278665ywi.349.1556033457993; Tue, 23 Apr 2019 08:30:57 -0700 (PDT) MIME-Version: 1.0 From: Shakeel Butt Date: Tue, 23 Apr 2019 08:30:46 -0700 Message-ID: Subject: [LSF/MM TOPIC] Proactive Memory Reclaim To: lsf-pc@lists.linux-foundation.org Cc: Linux MM , Michal Hocko , Johannes Weiner , Rik van Riel , Roman Gushchin Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Though this is quite late, I still want to propose a topic for discussion during LSFMM'19 which I think will be beneficial for Linux users in general but particularly the data center users running a range of different workloads and want to reduce the memory cost. Topic: Proactive Memory Reclaim Motivation/Problem: Memory overcommit is most commonly used technique to reduce the cost of memory by large infrastructure owners. However memory overcommit can adversely impact the performance of latency sensitive applications by triggering direct memory reclaim. Direct reclaim is unpredictable and disastrous for latency sensitive applications. Solution: Proactively reclaim memory from the system to drastically reduce the occurrences of direct reclaim. Target cold memory to keep the refault rate of the applications acceptable (i.e. no impact on the performance). Challenges: 1. Tracking cold memory efficiently. 2. Lack of infrastructure to reclaim specific memory. Details: Existing "Idle Page Tracking" allows tracking cold memory on a system but it becomes prohibitively expensive as the machine size grows. Also there is no way from the user space to reclaim a specific 'cold' page. I want to present our implementation of cold memory tracking and reclaim. The aim is to make it more generally beneficial to lot more users and upstream it. More details: "Software-driven far-memory in warehouse-scale computers", ASPLOS'19. https://youtu.be/aKddds6jn1s