From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932457AbbFIHNL (ORCPT ); Tue, 9 Jun 2015 03:13:11 -0400 Received: from mgwym02.jp.fujitsu.com ([211.128.242.41]:18722 "EHLO mgwym02.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078AbbFIHNH (ORCPT ); Tue, 9 Jun 2015 03:13:07 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.3.2 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20150223 X-SHieldMailCheckerMailID: 31733a9dd564438f9833c2c3d94846a6 Message-ID: <557691E0.5020203@jp.fujitsu.com> Date: Tue, 09 Jun 2015 16:12:32 +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 , Andrew Morton , nao.horiguchi@gmail.com, Yinghai Lu , "H. Peter Anvin" , Thomas Gleixner , mingo@elte.hu, Xiexiuqi , Hanjun Guo , "Luck, Tony" CC: Linux MM , LKML Subject: Re: [RFC PATCH 10/12] mm: add the buddy system interface References: <55704A7E.5030507@huawei.com> <55704CC4.8040707@huawei.com> In-Reply-To: <55704CC4.8040707@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 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. > + > + /* Alloc mirrored memory for both user and kernel */ > + if (sysctl_mirrorable) > + return true; Reading this, I think this sysctl is not good. The user cannot know what is mirrored because memory may not be mirrored until the sysctl is set. Thanks, -Kame > + > + return false; > +} > #endif > > /* > @@ -1796,7 +1816,10 @@ struct page *buffered_rmqueue(struct zone *preferred_zone, > WARN_ON_ONCE(order > 1); > } > spin_lock_irqsave(&zone->lock, flags); > - page = __rmqueue(zone, order, migratetype); > + if (is_migrate_mirror(migratetype)) > + page = __rmqueue_smallest(zone, order, migratetype); > + else > + page = __rmqueue(zone, order, migratetype); > spin_unlock(&zone->lock); > if (!page) > goto failed; > @@ -2928,6 +2951,11 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE) > alloc_flags |= ALLOC_CMA; > > +#ifdef CONFIG_MEMORY_MIRROR > + if (change_to_mirror(gfp_mask, ac.high_zoneidx)) > + ac.migratetype = MIGRATE_MIRROR; > +#endif > + > retry_cpuset: > cpuset_mems_cookie = read_mems_allowed_begin(); > > @@ -2943,9 +2971,19 @@ retry_cpuset: > > /* First allocation attempt */ > alloc_mask = gfp_mask|__GFP_HARDWALL; > +retry: > page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); > if (unlikely(!page)) { > /* > + * If there is no mirrored memory, we will alloc other > + * types memory. > + */ > + if (is_migrate_mirror(ac.migratetype)) { > + ac.migratetype = gfpflags_to_migratetype(gfp_mask); > + goto retry; > + } > + > + /* > * Runtime PM, block IO and its error handling path > * can deadlock because I/O on the device might not > * complete. >