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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74BADC433EF for ; Mon, 14 Mar 2022 15:21:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D72946B0072; Mon, 14 Mar 2022 11:21:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D21238D0002; Mon, 14 Mar 2022 11:21:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BE8008D0001; Mon, 14 Mar 2022 11:21:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0180.hostedemail.com [216.40.44.180]) by kanga.kvack.org (Postfix) with ESMTP id AF9D66B0072 for ; Mon, 14 Mar 2022 11:21:07 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 68EF7A3ECC for ; Mon, 14 Mar 2022 15:21:07 +0000 (UTC) X-FDA: 79243354974.29.81389AF Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by imf16.hostedemail.com (Postfix) with ESMTP id 6D14C180029 for ; Mon, 14 Mar 2022 15:21:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647271266; x=1678807266; h=message-id:date:mime-version:to:cc:references:from: subject:in-reply-to:content-transfer-encoding; bh=U3CvAktVdU1usYTq7NAeaK3m9HJMxau0P6laS9k8Lps=; b=kkxlB4w7cdK19iFds+OQgGQkth22UgetqSm85RkrORSpReLeUtoutaaj K6018Y+2HSzZsXWP44UxEiSW98vjj3E/Mrax9HY2Np49hxB7DF2YAaUiI NGhNoaU2x1dwipwgl7ZbvbVyfSlNcGQcsdHodAWYPgUv6CdOBa0vXg8gz QreBoCmG7ILib5VgIm/YbcokUScB9VxnXK+dVazEu4aCSwOK84uqSzjQ9 NYt1Ygkba17I2hMOFsTQhALy3HNykKNTFXq06obJzMBsSZYLFLXe9IQky NzALlCrvdEIyzeo+b6axTQDFYXxL0ReZAm/KPr73i8I7hLGKCzQ/mSYSK g==; X-IronPort-AV: E=McAfee;i="6200,9189,10285"; a="255783971" X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="255783971" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2022 08:21:04 -0700 X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="515467811" Received: from zborja-mobl1.amr.corp.intel.com (HELO [10.212.239.199]) ([10.212.239.199]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2022 08:21:04 -0700 Message-ID: <6b63d2ad-9b21-3fd6-37b4-31d7ad804c30@intel.com> Date: Mon, 14 Mar 2022 08:20:57 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Oscar Salvador , "Huang, Ying" Cc: Andrew Morton , Dave Hansen , Abhishek Goel , Baolin Wang , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220310120749.23077-1-osalvador@suse.de> <87mthxb514.fsf@yhuang6-desk2.ccr.corp.intel.com> <87czip73b4.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Dave Hansen Subject: Re: [PATCH v2] mm: Only re-generate demotion targets when a numa node changes its N_CPU state In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 6D14C180029 X-Rspam-User: Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=kkxlB4w7; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf16.hostedemail.com: domain of dave.hansen@intel.com has no SPF policy when checking 134.134.136.24) smtp.mailfrom=dave.hansen@intel.com X-Stat-Signature: nfj9rrzooqioo9ajmyt6kjdskpm7z5hd X-Rspamd-Server: rspam04 X-HE-Tag: 1647271266-51173 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 3/14/22 08:13, Oscar Salvador wrote: > On Mon, Mar 14, 2022 at 09:03:59AM +0800, Huang, Ying wrote: >> Oscar Salvador writes: >> On host machine, PMEM is always exposed via memory hotplug. But later >> on, we found that for guest system it's possible for PMEM to be exposed >> as normal memory. > Could you please elaborate on that? How is it done? I would love to hear the > details. Qemu, for instance, has a "mem-path" argument. It's typically used for using hugetlbfs as guest memory. But, there's nothing stopping you from pointing it to a DAX device or a file on a DAX filesystem that's backed by pmem.