From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752636AbbFYJtA (ORCPT ); Thu, 25 Jun 2015 05:49:00 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:57111 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105AbbFYJsv (ORCPT ); Thu, 25 Jun 2015 05:48:51 -0400 Message-ID: <558BCD95.2090201@huawei.com> Date: Thu, 25 Jun 2015 17:44:53 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Kamezawa Hiroyuki CC: Andrew Morton , , Yinghai Lu , "H. Peter Anvin" , "Thomas Gleixner" , , Xiexiuqi , Hanjun Guo , "Luck, Tony" , Linux MM , LKML Subject: Re: [RFC PATCH 10/12] mm: add the buddy system interface References: <55704A7E.5030507@huawei.com> <55704CC4.8040707@huawei.com> <557691E0.5020203@jp.fujitsu.com> <5576BA2B.6060907@huawei.com> <5577A9A9.7010108@jp.fujitsu.com> In-Reply-To: <5577A9A9.7010108@jp.fujitsu.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.558BCDB7.004A,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 51d9c3488dd5d28e4ad52ebf469d0786 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/6/10 11:06, Kamezawa Hiroyuki wrote: > On 2015/06/09 19:04, Xishi Qiu wrote: >> On 2015/6/9 15:12, Kamezawa Hiroyuki wrote: >> >>> On 2015/06/04 22:04, Xishi Qiu wrote: >>>> Add the buddy system interface for address range mirroring feature. >>>> Allocate mirrored pages in MIGRATE_MIRROR list. If there is no mirrored pages >>>> left, use other types pages. >>>> >>>> Signed-off-by: Xishi Qiu >>>> --- >>>> mm/page_alloc.c | 40 +++++++++++++++++++++++++++++++++++++++- >>>> 1 file changed, 39 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >>>> index d4d2066..0fb55288 100644 >>>> --- a/mm/page_alloc.c >>>> +++ b/mm/page_alloc.c >>>> @@ -599,6 +599,26 @@ static inline bool is_mirror_pfn(unsigned long pfn) >>>> >>>> return false; >>>> } >>>> + >>>> +static inline bool change_to_mirror(gfp_t gfp_flags, int high_zoneidx) >>>> +{ >>>> + /* >>>> + * Do not alloc mirrored memory below 4G, because 0-4G is >>>> + * all mirrored by default, and the list is always empty. >>>> + */ >>>> + if (high_zoneidx < ZONE_NORMAL) >>>> + return false; >>>> + >>>> + /* Alloc mirrored memory for only kernel */ >>>> + if (gfp_flags & __GFP_MIRROR) >>>> + return true; >>> >>> GFP_KERNEL itself should imply mirror, I think. >>> >> >> Hi Kame, >> >> How about like this: #define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_MIRROR) ? >> > > Hm.... it cannot cover GFP_ATOMIC at el. > > I guess, mirrored memory should be allocated if !__GFP_HIGHMEM or !__GFP_MOVABLE Hi Kame, Can we distinguish allocations form user or kernel only by GFP flags? Thanks, Xishi Qiu