Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933618AbaJWAlQ (ORCPT ); Wed, 22 Oct 2014 20:41:16 -0400 Received: from [42.62.48.242] ([42.62.48.242]:29681 "EHLO outbound.mxmail.xiaomi.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754359AbaJWAlO (ORCPT ); Wed, 22 Oct 2014 20:41:14 -0400 From: =?gb2312?B?1uy71A==?= To: Peter Hurley , Laura Abbott , "m.szyprowski@samsung.com" , "akpm@linux-foundation.org" , "riel@redhat.com" , "mgorman@suse.de" , "hughd@google.com" , "akinobu.mita@gmail.com" CC: "rjw@rjwysocki.net" , "len.brown@intel.com" , "pavel@ucw.cz" , "mina86@mina86.com" , "aneesh.kumar@linux.vnet.ibm.com" , "iamjoonsoo.kim@lge.com" , "hannes@cmpxchg.org" , "minchan@kernel.org" , "nasa4836@gmail.com" , "ddstreet@ieee.org" , "mingo@kernel.org" , "rientjes@google.com" , "peterz@infradead.org" , "keescook@chromium.org" , "atomlin@redhat.com" , "raistlin@linux.it" , "axboe@fb.com" , "paulmck@linux.vnet.ibm.com" , "kirill.shutemov@linux.intel.com" , "n-horiguchi@ah.jp.nec.com" , "k.khlebnikov@samsung.com" , "msalter@redhat.com" , "deller@gmx.de" , "tangchen@cn.fujitsu.com" , "ben@decadent.org.uk" , "vbabka@suse.cz" , "sasha.levin@oracle.com" , "vdavydov@parallels.com" , "suleiman@google.com" , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-mm@kvack.org" Subject: Re: [PATCH 0/4] (CMA_AGGRESSIVE) Make CMA memory be more aggressive about allocation Thread-Topic: [PATCH 0/4] (CMA_AGGRESSIVE) Make CMA memory be more aggressive about allocation Thread-Index: AQHP6PJVOSZsZeZKBkSR9KhOfKwh0g== Date: Thu, 23 Oct 2014 00:40:57 +0000 Message-ID: <04a07ed889c840f1919e220f906af3af@cnbox4.mioffice.cn> References: <1413430551-22392-1-git-send-email-zhuhui@xiaomi.com> <543F8812.2020002@codeaurora.org> <54479CB2.5040408@hurleysoftware.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [106.37.216.50] Content-Type: text/plain; charset="gb2312" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id s9N0fLid012047 On 10/22/14 20:02, Peter Hurley wrote: > On 10/16/2014 04:55 AM, Laura Abbott wrote: >> On 10/15/2014 8:35 PM, Hui Zhu wrote: >>> In fallbacks of page_alloc.c, MIGRATE_CMA is the fallback of >>> MIGRATE_MOVABLE. >>> MIGRATE_MOVABLE will use MIGRATE_CMA when it doesn't have a page in >>> order that Linux kernel want. >>> >>> If a system that has a lot of user space program is running, for >>> instance, an Android board, most of memory is in MIGRATE_MOVABLE and >>> allocated. Before function __rmqueue_fallback get memory from >>> MIGRATE_CMA, the oom_killer will kill a task to release memory when >>> kernel want get MIGRATE_UNMOVABLE memory because fallbacks of >>> MIGRATE_UNMOVABLE are MIGRATE_RECLAIMABLE and MIGRATE_MOVABLE. >>> This status is odd. The MIGRATE_CMA has a lot free memory but Linux >>> kernel kill some tasks to release memory. >>> >>> This patch series adds a new function CMA_AGGRESSIVE to make CMA memory >>> be more aggressive about allocation. >>> If function CMA_AGGRESSIVE is available, when Linux kernel call function >>> __rmqueue try to get pages from MIGRATE_MOVABLE and conditions allow, >>> MIGRATE_CMA will be allocated as MIGRATE_MOVABLE first. If MIGRATE_CMA >>> doesn't have enough pages for allocation, go back to allocate memory from >>> MIGRATE_MOVABLE. >>> Then the memory of MIGRATE_MOVABLE can be kept for MIGRATE_UNMOVABLE and >>> MIGRATE_RECLAIMABLE which doesn't have fallback MIGRATE_CMA. >>> >> >> It's good to see another proposal to fix CMA utilization. Do you have >> any data about the success rate of CMA contiguous allocation after >> this patch series? I played around with a similar approach of using >> CMA for MIGRATE_MOVABLE allocations and found that although utilization >> did increase, contiguous allocations failed at a higher rate and were >> much slower. I see what this series is trying to do with avoiding >> allocation from CMA pages when a contiguous allocation is progress. >> My concern is that there would still be problems with contiguous >> allocation after all the MIGRATE_MOVABLE fallback has happened. > > What impact does this series have on x86 platforms now that CMA is the > backup allocator for all iommu dma allocations? They will not affect driver CMA memory allocation. Thanks, Hui > > Regards, > Peter Hurley > ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?