From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752581AbbCZK2L (ORCPT ); Thu, 26 Mar 2015 06:28:11 -0400 Received: from cantor2.suse.de ([195.135.220.15]:60105 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751756AbbCZK2I (ORCPT ); Thu, 26 Mar 2015 06:28:08 -0400 Date: Thu, 26 Mar 2015 10:28:03 +0000 From: Mel Gorman To: Gioh Kim Cc: akpm@linux-foundation.org, riel@redhat.com, hannes@cmpxchg.org, rientjes@google.com, vdavydov@parallels.com, iamjoonsoo.kim@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com Subject: Re: [RFCv2] mm: page allocation for less fragmentation Message-ID: <20150326102803.GL4701@suse.de> References: <1427251155-12322-1-git-send-email-gioh.kim@lge.com> <20150325105640.GI4701@suse.de> <551325A6.5000405@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <551325A6.5000405@lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2015 at 06:16:22AM +0900, Gioh Kim wrote: > > > 2015-03-25 ?????? 7:56??? Mel Gorman ???(???) ??? ???: > >On Wed, Mar 25, 2015 at 11:39:15AM +0900, Gioh Kim wrote: > >>My driver allocates more than 40MB pages via alloc_page() at a time and > >>maps them at virtual address. Totally it uses 300~400MB pages. > >> > >>If I run a heavy load test for a few days in 1GB memory system, I cannot allocate even order=3 pages > >>because-of the external fragmentation. > >> > >>I thought I needed a anti-fragmentation solution for my driver. > >>But there is no allocation function that considers fragmentation. > >>The compaction is not helpful because it is only for movable pages, not unmovable pages. > >> > >>This patch proposes a allocation function allocates only pages in the same pageblock. > >> > > > >Is this not what CMA is for? Or creating a MOVABLE zone? > > It's not related to CMA and MOVABLE zone. > It's for compaction and anti-fragmentation for any zone. > Create a CMA area, allow your driver to use it use alloc_contig_range. As it is, this is creating another contiguous range allocation function with no in-kernel users. -- Mel Gorman SUSE Labs