Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752313AbcKGHsG (ORCPT ); Mon, 7 Nov 2016 02:48:06 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:30738 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270AbcKGHsF (ORCPT ); Mon, 7 Nov 2016 02:48:05 -0500 Subject: Re: [PATCH v6 2/6] mm/cma: introduce new zone, ZONE_CMA To: Joonsoo Kim References: <1476414196-3514-1-git-send-email-iamjoonsoo.kim@lge.com> <1476414196-3514-3-git-send-email-iamjoonsoo.kim@lge.com> <58184B28.8090405@hisilicon.com> <20161107061500.GA21159@js1304-P5Q-DELUXE> <58202881.5030004@hisilicon.com> <20161107072702.GC21159@js1304-P5Q-DELUXE> <582030CB.80905@hisilicon.com> CC: Andrew Morton , Rik van Riel , Johannes Weiner , , "Laura Abbott" , Minchan Kim , "Marek Szyprowski" , Michal Nazarewicz , "Aneesh Kumar K.V" , Vlastimil Babka , , , , Zhuangluan Su , Dan Zhao From: Chen Feng Message-ID: <5820313A.80207@hisilicon.com> Date: Mon, 7 Nov 2016 15:46:02 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <582030CB.80905@hisilicon.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.142.193.64] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1611 Lines: 49 On 2016/11/7 15:44, Chen Feng wrote: > On 2016/11/7 15:27, Joonsoo Kim wrote: >> On Mon, Nov 07, 2016 at 03:08:49PM +0800, Chen Feng wrote: >>> >>> >>> On 2016/11/7 14:15, Joonsoo Kim wrote: >>>> On Tue, Nov 01, 2016 at 03:58:32PM +0800, Chen Feng wrote: >>>>> Hello, I hava a question on cma zone. >>>>> >>>>> When we have cma zone, cma zone will be the highest zone of system. >>>>> >>>>> In android system, the most memory allocator is ION. Media system will >>>>> alloc unmovable memory from it. >>>>> >>>>> On low memory scene, will the CMA zone always do balance? >>>> >>>> Allocation request for low zone (normal zone) would not cause CMA zone >>>> to be balanced since it isn't helpful. >>>> >>> Yes. But the cma zone will run out soon. And it always need to do balance. >>> >>> How about use migrate cma before movable and let cma type to fallback movable. >>> >>> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1263745.html >> >> ZONE_CMA approach will act like as your solution. Could you elaborate >> more on the problem of zone approach? >> > > The ZONE approach is that makes cma pages in a zone. It can cause a higher swapin/out > than use migrate cma first. > > The higher swapin/out may have a performance effect to application. The application may > use too much time swapin memory. > > You can see my tested result attached for detail. And the baseline is result of [1]. > > My test case is run 60 applications and alloc 512MB ION memory. Repeat this action 50 times > [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1263745.html >> Thanks. >> >> . >>