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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 F2AECECE597 for ; Thu, 17 Oct 2019 17:34:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C5C6F20820 for ; Thu, 17 Oct 2019 17:34:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C5C6F20820 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6BED88E0016; Thu, 17 Oct 2019 13:34:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 66EFD8E0003; Thu, 17 Oct 2019 13:34:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 585558E0016; Thu, 17 Oct 2019 13:34:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0252.hostedemail.com [216.40.44.252]) by kanga.kvack.org (Postfix) with ESMTP id 387D58E0003 for ; Thu, 17 Oct 2019 13:34:51 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id DC04D815B for ; Thu, 17 Oct 2019 17:34:50 +0000 (UTC) X-FDA: 76053976740.12.town89_647c9cc3a4a39 X-HE-Tag: town89_647c9cc3a4a39 X-Filterd-Recvd-Size: 3161 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Thu, 17 Oct 2019 17:34:50 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 59D73300C727; Thu, 17 Oct 2019 17:34:49 +0000 (UTC) Received: from [10.36.117.42] (ovpn-117-42.ams2.redhat.com [10.36.117.42]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE5A25C1D8; Thu, 17 Oct 2019 17:34:47 +0000 (UTC) Subject: Re: [RFC] Memory Tiering To: "Verma, Vishal L" , "Williams, Dan J" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "Wu, Fengguang" , "Hansen, Dave" , "Huang, Ying" References: <0679872d-3d03-2fa3-5bd2-80f694357203@redhat.com> <2e193c88-f247-4c8f-f61c-c9b28303d62f@intel.com> <655c9d239ee1be425571aa1d71c681314e20984a.camel@intel.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <34ae126d-002b-b773-96c9-a78f7ef671e9@redhat.com> Date: Thu, 17 Oct 2019 19:34:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <655c9d239ee1be425571aa1d71c681314e20984a.camel@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Thu, 17 Oct 2019 17:34:49 +0000 (UTC) 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: On 17.10.19 19:07, Verma, Vishal L wrote: > > On Thu, 2019-10-17 at 07:17 -0700, Dave Hansen wrote: >> On 10/17/19 1:07 AM, David Hildenbrand wrote: >>> Very interesting topic. I heard similar demand from HPC folks >>> (especially involving other memory types ("tiers")). There, I think >>> you often want to let the application manage that. But of course, for >>> many applications an automatic management might already be >>> beneficial. >>> >>> Am I correct that you are using PMEM in this area along with >>> ZONE_DEVICE and not by giving PMEM to the buddy (add_memory())? >> >> The PMEM starts out as ZONE_DEVICE, but we unbind it from its original >> driver and bind it to this stub of a "driver": drivers/dax/kmem.c which >> uses add_memory() on it. >> >> There's some nice tooling inside the daxctl component of ndctl to do all >> the sysfs magic to make this happen. >> > Here is more info about the daxctl command in question: > > https://pmem.io/ndctl/daxctl-reconfigure-device.html > Thanks, yeah I saw the patches back then (I though they were by Pavel but they were actually by you :) ) to add the memory to the buddy (via add_memory()). Will explore some more, thanks! -- Thanks, David / dhildenb