Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752840AbcKUBuC (ORCPT ); Sun, 20 Nov 2016 20:50:02 -0500 Received: from mail-pg0-f67.google.com ([74.125.83.67]:33314 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752723AbcKUBuA (ORCPT ); Sun, 20 Nov 2016 20:50:00 -0500 Subject: Re: [HMM v13 04/18] mm/ZONE_DEVICE/free-page: callback when page is freed To: =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <1479493107-982-1-git-send-email-jglisse@redhat.com> <1479493107-982-5-git-send-email-jglisse@redhat.com> Cc: John Hubbard , Dan Williams , Ross Zwisler From: Balbir Singh Message-ID: <7ec714d6-6779-5abf-0607-862acddfbd4a@gmail.com> Date: Mon, 21 Nov 2016 12:49:55 +1100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <1479493107-982-5-git-send-email-jglisse@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 406 Lines: 12 On 19/11/16 05:18, Jérôme Glisse wrote: > When a ZONE_DEVICE page refcount reach 1 it means it is free and nobody > is holding a reference on it (only device to which the memory belong do). > Add a callback and call it when that happen so device driver can implement > their own free page management. > Could you give an example of what their own free page management might look like? Balbir Singh.