From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 599556B0274 for ; Wed, 26 Oct 2016 07:09:31 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id i85so150540767pfa.5 for ; Wed, 26 Oct 2016 04:09:31 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id s6si1699653pax.104.2016.10.26.04.09.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Oct 2016 04:09:30 -0700 (PDT) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u9QB92GJ076511 for ; Wed, 26 Oct 2016 07:09:29 -0400 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0a-001b2d01.pphosted.com with ESMTP id 26aqjw3u6u-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 26 Oct 2016 07:09:29 -0400 Received: from localhost by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 26 Oct 2016 05:09:28 -0600 From: "Aneesh Kumar K.V" Subject: Re: [RFC 0/8] Define coherent device memory node In-Reply-To: <20161025151637.GA6072@gmail.com> References: <1477283517-2504-1-git-send-email-khandual@linux.vnet.ibm.com> <20161024170902.GA5521@gmail.com> <87a8dtawas.fsf@linux.vnet.ibm.com> <20161025151637.GA6072@gmail.com> Date: Wed, 26 Oct 2016 16:39:19 +0530 MIME-Version: 1.0 Content-Type: text/plain Message-Id: <87y41bcqow.fsf@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Glisse Cc: Anshuman Khandual , linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, js1304@gmail.com, vbabka@suse.cz, mgorman@suse.de, minchan@kernel.org, akpm@linux-foundation.org, bsingharora@gmail.com Jerome Glisse writes: > On Tue, Oct 25, 2016 at 09:56:35AM +0530, Aneesh Kumar K.V wrote: >> Jerome Glisse writes: >> >> > On Mon, Oct 24, 2016 at 10:01:49AM +0530, Anshuman Khandual wrote: >> > >> I looked at the hmm-v13 w.r.t migration and I guess some form of device >> callback/acceleration during migration is something we should definitely >> have. I still haven't figured out how non addressable and coherent device >> memory can fit together there. I was waiting for the page cache >> migration support to be pushed to the repository before I start looking >> at this closely. >> > > The page cache migration does not touch the migrate code path. My issue with > page cache is writeback. The only difference with existing migrate code is > refcount check for ZONE_DEVICE page. Everything else is the same. What about the radix tree ? does file system migrate_page callback handle replacing normal page with ZONE_DEVICE page/exceptional entries ? > > For writeback i need to use a bounce page so basicly i am trying to hook myself > along the ISA bounce infrastructure for bio and i think it is the easiest path > to solve this in my case. > > In your case where block device can also access the device memory you don't > even need to use bounce page for writeback. > -aneesh -- 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