From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 0B09F6B0038 for ; Mon, 21 Nov 2016 23:55:06 -0500 (EST) Received: by mail-wm0-f69.google.com with SMTP id y16so2024117wmd.6 for ; Mon, 21 Nov 2016 20:55:05 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id p127si632182wmp.101.2016.11.21.20.55.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Nov 2016 20:55:05 -0800 (PST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uAM4rTXt143931 for ; Mon, 21 Nov 2016 23:55:03 -0500 Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) by mx0b-001b2d01.pphosted.com with ESMTP id 26vcxkcw0t-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 21 Nov 2016 23:55:03 -0500 Received: from localhost by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 22 Nov 2016 14:55:00 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 6B6493578053 for ; Tue, 22 Nov 2016 15:54:57 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id uAM4svSl3604842 for ; Tue, 22 Nov 2016 15:54:57 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id uAM4suoi024524 for ; Tue, 22 Nov 2016 15:54:57 +1100 Subject: Re: [HMM v13 05/18] mm/ZONE_DEVICE/devmem_pages_remove: allow early removal of device memory References: <1479493107-982-1-git-send-email-jglisse@redhat.com> <1479493107-982-6-git-send-email-jglisse@redhat.com> <5832CE7A.3060802@linux.vnet.ibm.com> <20161121123910.GE2392@redhat.com> From: Anshuman Khandual Date: Tue, 22 Nov 2016 10:24:54 +0530 MIME-Version: 1.0 In-Reply-To: <20161121123910.GE2392@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Message-Id: <5833CF9E.1030804@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Glisse Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, John Hubbard , Dan Williams , Ross Zwisler On 11/21/2016 06:09 PM, Jerome Glisse wrote: > On Mon, Nov 21, 2016 at 04:07:46PM +0530, Anshuman Khandual wrote: >> On 11/18/2016 11:48 PM, Jerome Glisse wrote: >>> HMM wants to remove device memory early before device tear down so add an >>> helper to do that. >> >> Could you please explain why HMM wants to remove device memory before >> device tear down ? >> > > Some device driver want to manage memory for several physical devices from a > single fake device driver. Because it fits their driver architecture better > and those physical devices can have dedicated link between them. > > Issue is that the fake device driver can outlive any of the real device for a > long time so we want to be able to remove device memory before the fake device > goes away to free up resources early. Got it. -- 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