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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED 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 48463C10F03 for ; Thu, 25 Apr 2019 07:41:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1407D214AE for ; Thu, 25 Apr 2019 07:41:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1407D214AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A3B646B0008; Thu, 25 Apr 2019 03:41:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A12316B000A; Thu, 25 Apr 2019 03:41:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92A7D6B000C; Thu, 25 Apr 2019 03:41:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id 5D02E6B0008 for ; Thu, 25 Apr 2019 03:41:45 -0400 (EDT) Received: by mail-pf1-f199.google.com with SMTP id y2so13534185pfn.13 for ; Thu, 25 Apr 2019 00:41:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:thread-topic:thread-index:date:message-id:references :in-reply-to:accept-language:content-language:dlp-product :dlp-version:dlp-reaction:content-transfer-encoding:mime-version; bh=G7gHHEOfNuEraVFjYBmCdx8NSVgzWxsQE56lW7FZBzE=; b=YsqfCPc7xPhjCGSAXkZMQPujKUT0dTZ6Arfe3k7VZLVwOzCAVx+0Ft6uL2aDvMlGt0 c6V0tgFLkTMcWMyaDGExGQl950Bu9GXmGrbesKZ9B2NN7EqVqqmLVq1FZO3SmhcRelOr x7gR0i0Dhx5ePdcbnmSQfai4ivFjaz5b8BBiGT4Gw4L/zCFjilnOLHXSxqfx4wkcFbvX v0I75sMlDnZBt18lukE3QoafOS7RNYTEYhc54iE6+cYjL/gsTuuu9t6k+Wqv0MHXHsXO KIR1agE/tgcEX9WKkp2yaIkxt3oHTE1vPAaDfIUY+WUXFTrgOoZqfZUM+bI87BtWwnQC 5L/w== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of fan.du@intel.com designates 192.55.52.88 as permitted sender) smtp.mailfrom=fan.du@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APjAAAVP81iJs7ShStizOCl+VmPcc4geWD1uAY8t/Jmxo6qxH9bQmMcb 3PFQxNf03WIyIH/sZ3UFf45M+neeIQsUC9VGOE4FmqqJP/Tqj4rpId59FwVCbfGlT2a4WzBYKJJ ufEaVjq+rwg8JJJfdQRV8q3xAyeKzuKEQiDCahBt3ytqvs2gZb1JscJ9FJMXuKSL8wg== X-Received: by 2002:a63:ff04:: with SMTP id k4mr21217805pgi.117.1556178104983; Thu, 25 Apr 2019 00:41:44 -0700 (PDT) X-Google-Smtp-Source: APXvYqwY36oVnr1jlkPw8jhOgsSMcduNZ4Hk6BSrQ2VqL6L/JXFHZVjEXUatMhFmWIDcOQn5Bu/v X-Received: by 2002:a63:ff04:: with SMTP id k4mr21217751pgi.117.1556178104114; Thu, 25 Apr 2019 00:41:44 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556178104; cv=none; d=google.com; s=arc-20160816; b=cQ0VaiZmP7u9bz+eTiDmF/mZPH5+o/Jz5KPjV25petQjMVPlqgwvSfEvWfaekm6c5F RWHfphSbXQLeCw3k8x4Xxu5VxMA/PVsIDBXjjBjpnoC6R6i1O2nIpEXqj1GPS+l/f66F AuiFCiL29kRVZjNshe6ocrp6wepR/4lHqlZtVA8tho95iu3N0TIZnIOYZSv3ovo13WS1 qncpWbqHz2Tf/wbEiKSec1S/YFxS2rqRMch/0KZ9khh2gY1kWR6ltnpChW/kAM57mylT UduR28Q5kdw0AqkSWbrb0vtbK3/XvWTflQ41Hipmmgo0ORPXLzFW92yS3iOIltCyLE7N qykw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:dlp-reaction:dlp-version :dlp-product:content-language:accept-language:in-reply-to:references :message-id:date:thread-index:thread-topic:subject:cc:to:from; bh=G7gHHEOfNuEraVFjYBmCdx8NSVgzWxsQE56lW7FZBzE=; b=hZEQ2cdgIarUbvRM5wciYiSBt20jQviDcyNCt/gMmvuXKRNC7/iZgn8kzvXg5avk2u o9Ecy3mjoX9OvBfwsVFiUVuXzHNm4ZnOoaX/RpiQu29bOe+lweQbjeyZWSUnIdyuW9wO WFOSZg0iFmUtaUdOjxAHT94ESv6uYO1mYuS0hszbVr93KhgGCnlVg+EzTNw6HOn1ylBa mmQU6iTl3BxnvYbCDFvSpsyxcVQUMf/fdrvKDXIZRzswvsKr7AGuk80p8BSb777FGzWY 935NOcAJOgeEqEpXSQ41dT5F8fnHaV738c3cKUxLAUd4PBDVES+qhEHCg4ooY20dh3yi GAHw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of fan.du@intel.com designates 192.55.52.88 as permitted sender) smtp.mailfrom=fan.du@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id m12si20130152pgc.157.2019.04.25.00.41.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Apr 2019 00:41:44 -0700 (PDT) Received-SPF: pass (google.com: domain of fan.du@intel.com designates 192.55.52.88 as permitted sender) client-ip=192.55.52.88; Authentication-Results: mx.google.com; spf=pass (google.com: domain of fan.du@intel.com designates 192.55.52.88 as permitted sender) smtp.mailfrom=fan.du@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Apr 2019 00:41:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,393,1549958400"; d="scan'208";a="340645474" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by fmsmga006.fm.intel.com with ESMTP; 25 Apr 2019 00:41:43 -0700 Received: from fmsmsx157.amr.corp.intel.com (10.18.116.73) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 25 Apr 2019 00:41:43 -0700 Received: from shsmsx107.ccr.corp.intel.com (10.239.4.96) by FMSMSX157.amr.corp.intel.com (10.18.116.73) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 25 Apr 2019 00:41:42 -0700 Received: from shsmsx104.ccr.corp.intel.com ([169.254.5.92]) by SHSMSX107.ccr.corp.intel.com ([169.254.9.153]) with mapi id 14.03.0415.000; Thu, 25 Apr 2019 15:41:41 +0800 From: "Du, Fan" To: Michal Hocko CC: "akpm@linux-foundation.org" , "Wu, Fengguang" , "Williams, Dan J" , "Hansen, Dave" , "xishi.qiuxishi@alibaba-inc.com" , "Huang, Ying" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "Du, Fan" Subject: RE: [RFC PATCH 0/5] New fallback workflow for heterogeneous memory system Thread-Topic: [RFC PATCH 0/5] New fallback workflow for heterogeneous memory system Thread-Index: AQHU+wguqC0/BskpLkaHU1TotE//DKZL5oWAgACMEvA= Date: Thu, 25 Apr 2019 07:41:40 +0000 Message-ID: <5A90DA2E42F8AE43BC4A093BF067884825785EE8@SHSMSX104.ccr.corp.intel.com> References: <1556155295-77723-1-git-send-email-fan.du@intel.com> <20190425063727.GJ12751@dhcp22.suse.cz> In-Reply-To: <20190425063727.GJ12751@dhcp22.suse.cz> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYTAwMTA2OGUtZjhlYy00ZDA5LWE0MWQtZWI5ZTMyOWQ3ZWY3IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiYTdHdVZlWVhvblh5XC9BV0FNcFZEd2RJZElMUEFwbERINElTOVdaK0FTRHBGK01PcWpLZ3hCN3J3SHNaZngxS2cifQ== x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.600.7 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 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: >-----Original Message----- >From: Michal Hocko [mailto:mhocko@kernel.org] >Sent: Thursday, April 25, 2019 2:37 PM >To: Du, Fan >Cc: akpm@linux-foundation.org; Wu, Fengguang ; >Williams, Dan J ; Hansen, Dave >; xishi.qiuxishi@alibaba-inc.com; Huang, Ying >; linux-mm@kvack.org; linux-kernel@vger.kernel.org >Subject: Re: [RFC PATCH 0/5] New fallback workflow for heterogeneous >memory system > >On Thu 25-04-19 09:21:30, Fan Du wrote: >[...] >> However PMEM has different characteristics from DRAM, >> the more reasonable or desirable fallback style would be: >> DRAM node 0 -> DRAM node 1 -> PMEM node 2 -> PMEM node 3. >> When DRAM is exhausted, try PMEM then. > >Why and who does care? NUMA is fundamentally about memory nodes with >different access characteristics so why is PMEM any special? Michal, thanks for your comments! The "different" lies in the local or remote access, usually the underlying memory is the same type, i.e. DRAM. By "special", PMEM is usually in gigantic capacity than DRAM per dimm,=20 while with different read/write access latency than DRAM. Iow PMEM sits right under DRAM in the memory tier hierarchy. This makes PMEM to be far memory, or second class memory. So we give first class DRAM page to user, fallback to PMEM when necessary. The Cloud Service Provider can use DRAM + PMEM in their system, Leveraging method [1] to keep hot page in DRAM and warm or cold Page in PMEM, achieve optimal performance and reduce total cost of ownership at the same time. [1]: https://github.com/fengguang/memory-optimizer >-- >Michal Hocko >SUSE Labs