From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f46.google.com (mail-wg0-f46.google.com [74.125.82.46]) by kanga.kvack.org (Postfix) with ESMTP id 138306B0038 for ; Fri, 26 Jun 2015 07:26:48 -0400 (EDT) Received: by wgck11 with SMTP id k11so86076584wgc.0 for ; Fri, 26 Jun 2015 04:26:47 -0700 (PDT) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com. [119.145.14.66]) by mx.google.com with ESMTPS id eo2si57942489wjd.180.2015.06.26.04.26.45 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 26 Jun 2015 04:26:46 -0700 (PDT) Message-ID: <558D368F.8030900@huawei.com> Date: Fri, 26 Jun 2015 19:25:03 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH] mm: fix set pageblock migratetype when boot References: <558D24C1.5020901@huawei.com> <20150626110424.GI26927@suse.de> In-Reply-To: <20150626110424.GI26927@suse.de> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Vlastimil Babka , Johannes Weiner , iamjoonsoo.kim@lge.com, David Rientjes , sasha.levin@oracle.com, Linux MM , LKML On 2015/6/26 19:04, Mel Gorman wrote: > On Fri, Jun 26, 2015 at 06:09:05PM +0800, Xishi Qiu wrote: >> memmap_init_zone() >> ... >> if ((z->zone_start_pfn <= pfn) >> && (pfn < zone_end_pfn(z)) >> && !(pfn & (pageblock_nr_pages - 1))) >> set_pageblock_migratetype(page, MIGRATE_MOVABLE); >> ... >> >> If the pfn does not align to pageblock, it will not init the migratetype. > > What important impact does that have? It should leave a partial pageblock > as MIGRATE_UNMOVABLE which is fine by me. > Hi Mel, The impact is less, it's OK to ignore it. Thanks, Xishi Qiu >> So call it for every page, it will takes more time, but it doesn't matter, >> this function will be called only in boot or hotadd memory. >> > > It's a lot of additional overhead to add to memory initialisation. It > would need to be for an excellent reason with no alternative solution. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org