From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Burakov, Anatoly" Subject: Re: [PATCH] eal: add request to map reserved physical memory Date: Thu, 12 Apr 2018 15:35:53 +0100 Message-ID: References: <20180328045120.40098-1-ajit.khaparde@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Srinath Mannam , Scott Branden To: Ajit Khaparde , dev@dpdk.org Return-path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id 07D001C0F5 for ; Thu, 12 Apr 2018 16:36:03 +0200 (CEST) In-Reply-To: <20180328045120.40098-1-ajit.khaparde@broadcom.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 28-Mar-18 5:51 AM, Ajit Khaparde wrote: > From: Srinath Mannam > > Reserved physical memory is requested from kernel > and it will be mapped to user space. > This memory will be mapped to IOVA using VFIO. > And this memory will be provided to SPDK to allocate > NVMe CQs. > > Signed-off-by: Srinath Mannam > Signed-off-by: Scott Branden > Signed-off-by: Ajit Khaparde > --- Hi Srinath, I've seen this kind of approach implemented before to add additional memory types to DPDK (redefining "unused" socket id's to mean something else), and i don't like it. What would be better is to design a new API to support different memory types. Some groundwork for this was already laid for this release (switching to memseg lists), but more changes will be needed down the line. My ideal approach would be to have pluggable memory allocators. I've outlined some of my thoughts on this before [1], you're welcome to join/continue that discussion, and make sure whatever comes out of it is going to be useful for all of us :) I was planning to (attempt to) restart that discussion, and this seems like as good an opportunity to do that as any other. Now that the memory hotplug stuff is merged, i'll hopefully get more time prototyping. So, as it is, it's a NACK from me, but let's work together on something better :) [1] http://dpdk.org/ml/archives/dev/2018-February/090937.html -- Thanks, Anatoly