From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id B9B856B0038 for ; Mon, 1 May 2017 20:04:36 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id 184so257372wmy.18 for ; Mon, 01 May 2017 17:04:36 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id g207si10253506wme.150.2017.05.01.17.04.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 May 2017 17:04:35 -0700 (PDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v41Ns6M0036110 for ; Mon, 1 May 2017 20:04:34 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0b-001b2d01.pphosted.com with ESMTP id 2a6afvadws-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 01 May 2017 20:04:34 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 1 May 2017 20:04:33 -0400 Date: Mon, 1 May 2017 19:04:25 -0500 From: Reza Arbab Subject: Re: [RFC 0/4] RFC - Coherent Device Memory (Not for inclusion) References: <20170419075242.29929-1-bsingharora@gmail.com> <91272c14-81df-9529-f0ae-6abb17a694ea@nvidia.com> <20170501210415.aeuvd73auomvdmba@arbab-laptop.localdomain> <20170501235123.2k372i75vxlw5n75@arbab-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Message-Id: <20170502000424.kauqofpp6gxokcmj@arbab-vm> Sender: owner-linux-mm@kvack.org List-ID: To: John Hubbard Cc: Balbir Singh , linux-mm@kvack.org, akpm@linux-foundation.org, khandual@linux.vnet.ibm.com, benh@kernel.crashing.org, aneesh.kumar@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, srikar@linux.vnet.ibm.com, haren@linux.vnet.ibm.com, jglisse@redhat.com, mgorman@techsingularity.net, mhocko@kernel.org, vbabka@suse.cz, cl@linux.com On Mon, May 01, 2017 at 04:58:14PM -0700, John Hubbard wrote: >On 05/01/2017 04:51 PM, Reza Arbab wrote: >>On Mon, May 01, 2017 at 02:56:34PM -0700, John Hubbard wrote: >>>On 05/01/2017 02:04 PM, Reza Arbab wrote: >>>>On Mon, May 01, 2017 at 01:41:55PM -0700, John Hubbard wrote: >>>>>1. A way to move pages between NUMA nodes, both virtual >>>>>address and physical address-based, from kernel mode. >>>> >>>>Jerome's migrate_vma() and migrate_dma() should have this >>>>covered, including DMA-accelerated copy. >>> >>>Yes, that's good. I wasn't sure from this discussion here if >>>either or both of those would be used, but now I see. >>> >>>Are those APIs ready for moving pages between NUMA nodes? As there >>>is no NUMA node id in the API, are we relying on the pages' >>>membership (using each page and updating which node it is on)? >> >>Yes. Those APIs work by callback. The alloc_and_copy() function you >>provide will be called at the appropriate point in the migration. >>Yours would allocate from a specific destination node, and copy >>using DMA. >> > >hmmm, that reminds me: the whole story of "which device is this, and >which NUMA node does it correlate to?" will have to be wired up. That >is *probably* all in the device driver, but since I haven't worked >through it, I'd be inclined to list it as an item on the checklist, >just in case it requires some little hook in the upstream kernel. I've worked this out. It can be contained to the driver itself. -- Reza Arbab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org