From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by kanga.kvack.org (Postfix) with ESMTP id 16AEE6B0038 for ; Fri, 26 Jun 2015 07:04:30 -0400 (EDT) Received: by wiwl6 with SMTP id l6so42225179wiw.0 for ; Fri, 26 Jun 2015 04:04:29 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id z8si2296806wiy.3.2015.06.26.04.04.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 26 Jun 2015 04:04:28 -0700 (PDT) Date: Fri, 26 Jun 2015 12:04:24 +0100 From: Mel Gorman Subject: Re: [PATCH] mm: fix set pageblock migratetype when boot Message-ID: <20150626110424.GI26927@suse.de> References: <558D24C1.5020901@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <558D24C1.5020901@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Andrew Morton , Vlastimil Babka , Johannes Weiner , iamjoonsoo.kim@lge.com, David Rientjes , sasha.levin@oracle.com, Linux MM , LKML 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. > 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. -- Mel Gorman SUSE Labs -- 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