From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BB80C282D8 for ; Wed, 30 Jan 2019 17:48:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB364218A4 for ; Wed, 30 Jan 2019 17:48:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548870532; bh=AXR0llYBRGSYiE2vpUusekrrRCdQMUUkAr120z4LWrI=; h=Date:From:To:Cc:Subject:List-ID:From; b=oCMuGuN4wbwtvxtY3dsaCTP9XkKUCjjCmsWAChNL6iuc3VgRNA0r+jq2xYH9ah4mR fzWfjFOb1JFQt2IGjQnWRO80kTnGdL++Xgn3nA1hMacfN/rq6Uw6FSNE41rN3QvCRz PClTmF9zXwEwB8bqXSzPbQeMmZ+Q8S5Ehq00Lr3A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732698AbfA3Rsu (ORCPT ); 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