From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752454AbdFOIMo (ORCPT ); Thu, 15 Jun 2017 04:12:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:44947 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752140AbdFOIMn (ORCPT ); Thu, 15 Jun 2017 04:12:43 -0400 Date: Thu, 15 Jun 2017 10:12:40 +0200 From: Michal Hocko To: Mike Kravetz Cc: linux-mm@kvack.org, Naoya Horiguchi , Mel Gorman , Vlastimil Babka , Andrew Morton , LKML Subject: Re: [RFC PATCH 2/4] hugetlb: add support for preferred node to alloc_huge_page_nodemask Message-ID: <20170615081239.GC1486@dhcp22.suse.cz> References: <20170613090039.14393-1-mhocko@kernel.org> <20170613090039.14393-3-mhocko@kernel.org> <3ac3d6a8-b62f-2386-cb04-f32b3bebffe7@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ac3d6a8-b62f-2386-cb04-f32b3bebffe7@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 14-06-17 17:12:31, Mike Kravetz wrote: > On 06/14/2017 03:12 PM, Mike Kravetz wrote: > > On 06/13/2017 02:00 AM, Michal Hocko wrote: > >> From: Michal Hocko > >> > >> alloc_huge_page_nodemask tries to allocate from any numa node in the > >> allowed node mask starting from lower numa nodes. This might lead to > >> filling up those low NUMA nodes while others are not used. We can reduce > >> this risk by introducing a concept of the preferred node similar to what > >> we have in the regular page allocator. We will start allocating from the > >> preferred nid and then iterate over all allowed nodes in the zonelist > >> order until we try them all. > >> > >> This is mimicking the page allocator logic except it operates on > >> per-node mempools. dequeue_huge_page_vma already does this so distill > >> the zonelist logic into a more generic dequeue_huge_page_nodemask > >> and use it in alloc_huge_page_nodemask. > >> > >> Signed-off-by: Michal Hocko > >> --- > > > > > > I built attempts/hugetlb-zonelists, threw it on a test machine, ran the > > libhugetlbfs test suite and saw failures. The failures started with this > > patch: commit 7e8b09f14495 in your tree. I have not yet started to look > > into the failures. It is even possible that the tests are making bad > > assumptions, but there certainly appears to be changes in behavior visible > > to the application(s). > > nm. The failures were the result of dequeue_huge_page_nodemask() always > returning NULL. Vlastimil already noticed this issue and provided a > solution. I have pushed my current version to the same branch. -- Michal Hocko SUSE Labs