From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752258AbbCYK4s (ORCPT ); Wed, 25 Mar 2015 06:56:48 -0400 Received: from cantor2.suse.de ([195.135.220.15]:45365 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752207AbbCYK4q (ORCPT ); Wed, 25 Mar 2015 06:56:46 -0400 Date: Wed, 25 Mar 2015 10:56:40 +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: <20150325105640.GI4701@suse.de> References: <1427251155-12322-1-git-send-email-gioh.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1427251155-12322-1-git-send-email-gioh.kim@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 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? -- Mel Gorman SUSE Labs