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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 078FAC282D7 for ; Wed, 30 Jan 2019 18:13:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D365520870 for ; Wed, 30 Jan 2019 18:13:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732873AbfA3SNI (ORCPT ); Wed, 30 Jan 2019 13:13:08 -0500 Received: from mga02.intel.com ([134.134.136.20]:25848 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbfA3SNI (ORCPT ); Wed, 30 Jan 2019 13:13:08 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jan 2019 10:13:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,541,1539673200"; d="scan'208";a="113978754" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga008.jf.intel.com with ESMTP; 30 Jan 2019 10:13:07 -0800 Date: Wed, 30 Jan 2019 11:12:22 -0700 From: Keith Busch To: Michal Hocko Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, LKML , linux-nvme@lists.infradead.org Subject: Re: [LSF/MM TOPIC] memory reclaim with NUMA rebalancing Message-ID: <20190130181221.GA19525@localhost.localdomain> References: <20190130174847.GD18811@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190130174847.GD18811@dhcp22.suse.cz> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 30, 2019 at 06:48:47PM +0100, Michal Hocko wrote: > 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. Yes, thanks for the proposal. I would be very interested in this discussion for MM. I think some of the details for determining such a migration path are related to the heterogeneous memory attributes I'm currently trying to export.