Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751862AbbFYXzP (ORCPT ); Thu, 25 Jun 2015 19:55:15 -0400 Received: from mgwkm04.jp.fujitsu.com ([202.219.69.171]:36888 "EHLO mgwkm04.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751558AbbFYXzL (ORCPT ); Thu, 25 Jun 2015 19:55:11 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.3.2 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20150223 X-SHieldMailCheckerMailID: 01e5606d1dd2407b8bd8e4a7920ef802 Message-ID: <558C94BB.1060304@jp.fujitsu.com> Date: Fri, 26 Jun 2015 08:54:35 +0900 From: Kamezawa Hiroyuki User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Xishi Qiu CC: Andrew Morton , nao.horiguchi@gmail.com, Yinghai Lu , "H. Peter Anvin" , Thomas Gleixner , mingo@elte.hu, 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> <558BCD95.2090201@huawei.com> In-Reply-To: <558BCD95.2090201@huawei.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2279 Lines: 76 On 2015/06/25 18:44, Xishi Qiu wrote: > 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? > Allocation from user and file caches are now *always* done with __GFP_MOVABLE. By this, pages will be allocated from MIGRATE_MOVABLE migration type. MOVABLE migration type means it's can be the target for page compaction or memory-hot-remove. Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/