From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx111.postini.com [74.125.245.111]) by kanga.kvack.org (Postfix) with SMTP id 5089F6B0031 for ; Mon, 5 Aug 2013 21:52:13 -0400 (EDT) Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 6 Aug 2013 07:13:44 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id B44BD394004D for ; Tue, 6 Aug 2013 07:21:55 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r761pxdK47317092 for ; Tue, 6 Aug 2013 07:21:59 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r761q1Ip030909 for ; Tue, 6 Aug 2013 07:22:02 +0530 From: "Aneesh Kumar K.V" Subject: Re: [PATCH 8/8] prepare to remove /proc/sys/vm/hugepages_treat_as_movable In-Reply-To: <1375411396-bw4cbhso-mutt-n-horiguchi@ah.jp.nec.com> References: <1374728103-17468-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1374728103-17468-9-git-send-email-n-horiguchi@ah.jp.nec.com> <87k3k7q4ox.fsf@linux.vnet.ibm.com> <1375302249-scfvftrh-mutt-n-horiguchi@ah.jp.nec.com> <87vc3qvtmc.fsf@linux.vnet.ibm.com> <1375411396-bw4cbhso-mutt-n-horiguchi@ah.jp.nec.com> Date: Tue, 06 Aug 2013 07:22:02 +0530 Message-ID: <87haf3oabh.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , linux-mm@kvack.org, Mel Gorman , Hugh Dickins , KOSAKI Motohiro , Andi Kleen , Hillf Danton , Michal Hocko , Rik van Riel , Wanpeng Li , linux-kernel@vger.kernel.org, Naoya Horiguchi Naoya Horiguchi writes: >> >> Considering that we have architectures that won't support migrating >> explicit hugepages with this patch series, is it ok to use >> GFP_HIGHUSER_MOVABLE for hugepage allocation ? > > Originally this parameter was introduced to make hugepage pool on ZONE_MOVABLE. > The benefit is that we can extend the hugepage pool more easily, > because external fragmentation less likely happens than other zone type > by rearranging fragmented pages with page migration/reclaim. > > So I think using ZONE_MOVABLE for hugepage allocation by default makes sense > even on the architectures which don't support hugepage migration. But allocating hugepages from ZONE_MOVABLE means we have pages in that zone which we can't migrate. Doesn't that impact other features like hotplug ? -aneesh -- 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