Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp6162831imu; Wed, 30 Jan 2019 09:49:59 -0800 (PST) X-Google-Smtp-Source: AHgI3IbtaC3aIcxT+AdqzZ740yXbhWzZV38NLf2Re9DcDgK7ofZ//JSUi4FTOOiV+kUbgYHWxjcE X-Received: by 2002:aa7:868f:: with SMTP id d15mr5863812pfo.225.1548870599860; Wed, 30 Jan 2019 09:49:59 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1548870599; cv=none; d=google.com; s=arc-20160816; b=OUS9CNgGvC7rB4vdfE35/SLmQoqXKiqEE647P5WvAUjErlcTGajFXNSk8CRkIU5rKm Fww1MuxZjKZLcJveIgTdfCW4Xp7Zk2TWs1fG2C4LYOhhQjQMdE2HxoYpJWXi6mannQmN 04GoR7g/W2ZGwD9ZCJiinivqZgjk97vfltYM6+IMaSRVJj2vcQXZ1oLXH7pwXS7yIz+a 5vQ0Av0b8xY81VnAbAvk6eBCdjw0S8pCkmvwVwszw0y+nKydcVwbS03jBNLVsY+594++ aXWniAcon/59B74tnwnwfETT9iaf/jz6nA2sHp8Me/3W1jMv3FuKzuGX+4odeomAb7IH i+1Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:content-disposition :mime-version:message-id:subject:cc:to:from:date; bh=FAICS1X5uNueQMhHI3a9DeQr2UwTRU34p4ZwdE7x/Bo=; b=WPAY8pDKSNc0y9XTQES5lEzIWnTZdnpb4z7rj8E0+AHCYXidGaJCWCwWIWGYMcASAH CrZOolnPUUxpq/yMu01IQ0K+BQP5z5qsaAwR/dGyWEGJjeHqJuK7OEE+fX9OgxE7zYAB LeUV8reeAMyJhW+RhgkY62bU9hs5joLfDHVs5GIcRvWQIZdd2RCuz+5uQR7Ho/yIf7mW s72EMV+PROBy1d6rIFrE/kmZg+GFgYsv7NWpcQxtxkouJE5LjJae3Vm3xF+Hzd7nI4X0 ChnMdtP3UlRLRvILrcboKuScKlfnM/Zka4aOwGozZuH/Muj531oarGpB/AxDKMqFoePp Mvpg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id j28si1882271pgm.160.2019.01.30.09.49.42; Wed, 30 Jan 2019 09:49:59 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732691AbfA3Rsu (ORCPT + 99 others); Wed, 30 Jan 2019 12:48:50 -0500 Received: from mx2.suse.de ([195.135.220.15]:45740 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728479AbfA3Rsu (ORCPT ); Wed, 30 Jan 2019 12:48:50 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 77E1DAF96; Wed, 30 Jan 2019 17:48:48 +0000 (UTC) Date: Wed, 30 Jan 2019 18:48:47 +0100 From: Michal Hocko To: lsf-pc@lists.linux-foundation.org Cc: linux-mm@kvack.org, LKML , linux-nvme@lists.infradead.org Subject: [LSF/MM TOPIC] memory reclaim with NUMA rebalancing Message-ID: <20190130174847.GD18811@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I would like to propose the following topic for the MM track. Different group of people would like to use NVIDMMs as a low cost & slower memory which is presented to the system as a NUMA node. We do have a NUMA API but it doesn't really fit to "balance the memory between nodes" needs. People would like to have hot pages in the regular RAM while cold pages might be at lower speed NUMA nodes. We do have NUMA balancing for promotion path but there is notIhing for the other direction. Can we start considering memory reclaim to move pages to more distant and idle NUMA nodes rather than reclaim them? There are certainly details that will get quite complicated but I guess it is time to start discussing this at least. -- Michal Hocko SUSE Labs