From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751568AbbFZBvG (ORCPT ); Thu, 25 Jun 2015 21:51:06 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:61739 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbbFZBvA (ORCPT ); Thu, 25 Jun 2015 21:51:00 -0400 Message-ID: <558CAE43.4090702@huawei.com> Date: Fri, 26 Jun 2015 09:43:31 +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> <558BCD95.2090201@huawei.com> <558C94BB.1060304@jp.fujitsu.com> In-Reply-To: <558C94BB.1060304@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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/6/26 7:54, Kamezawa Hiroyuki wrote: > 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 > So if we want all kernel memory allocated from mirror, how about change like this? __alloc_pages_nodemask() gfpflags_to_migratetype() if (!(gfp_mask & __GFP_MOVABLE)) return MIGRATE_MIRROR Thanks, Xishi Qiu > > > > > > > > . >