From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751607AbdG0IAj (ORCPT ); Thu, 27 Jul 2017 04:00:39 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:38036 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbdG0IAi (ORCPT ); Thu, 27 Jul 2017 04:00:38 -0400 Subject: Re: gigantic hugepages vs. movable zones To: Michal Hocko Cc: Luiz Capitulino , Mike Kravetz , linux-mm@kvack.org, LKML References: <20170726105004.GI2981@dhcp22.suse.cz> <87inie1uwf.fsf@linux.vnet.ibm.com> <20170727072857.GI20970@dhcp22.suse.cz> From: "Aneesh Kumar K.V" Date: Thu, 27 Jul 2017 13:30:31 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170727072857.GI20970@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17072708-0044-0000-0000-0000037410E6 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007433; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00893538; UDB=6.00446721; IPR=6.00673698; BA=6.00005492; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016402; XFM=3.00000015; UTC=2017-07-27 08:00:35 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072708-0045-0000-0000-000007A21BBA Message-Id: <1529e986-5f28-35dd-c82e-a4b5801b4afd@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-27_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1707270130 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/27/2017 12:58 PM, Michal Hocko wrote: > On Thu 27-07-17 07:52:08, Aneesh Kumar K.V wrote: >> Michal Hocko writes: >> >>> Hi, >>> I've just noticed that alloc_gigantic_page ignores movability of the >>> gigantic page and it uses any existing zone. Considering that >>> hugepage_migration_supported only supports 2MB and pgd level hugepages >>> then 1GB pages are not migratable and as such allocating them from a >>> movable zone will break the basic expectation of this zone. Standard >>> hugetlb allocations try to avoid that by using htlb_alloc_mask and I >>> believe we should do the same for gigantic pages as well. >>> >>> I suspect this behavior is not intentional. What do you think about the >>> following untested patch? >> >> >> I also noticed an unrelated issue with the usage of >> start_isolate_page_range. On error we set the migrate type to >> MIGRATE_MOVABLE. > > Why that should be a problem? I think it is perfectly OK to have > MIGRATE_MOVABLE pageblocks inside kernel zones. > we can pick pages with migrate type movable and if we fail to isolate won't we set the migrate type of that pages to MOVABLE ? -aneesh