Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932884AbbFIKNH (ORCPT ); Tue, 9 Jun 2015 06:13:07 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:12834 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753533AbbFIKM6 (ORCPT ); Tue, 9 Jun 2015 06:12:58 -0400 Message-ID: <5576BA2B.6060907@huawei.com> Date: Tue, 9 Jun 2015 18:04:27 +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> In-Reply-To: <557691E0.5020203@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 Content-Length: 3609 Lines: 120 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) ? Thanks, Xishi Qiu >> + >> + /* 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. >> > > > > . > -- 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/