Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752072AbdLTFfZ convert rfc822-to-8bit (ORCPT ); Wed, 20 Dec 2017 00:35:25 -0500 Received: from tyo161.gate.nec.co.jp ([114.179.232.161]:33326 "EHLO tyo161.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751848AbdLTFfW (ORCPT ); Wed, 20 Dec 2017 00:35:22 -0500 From: Naoya Horiguchi To: Michal Hocko CC: Naoya Horiguchi , Mike Kravetz , "linux-mm@kvack.org" , "Andrew Morton" , LKML Subject: Re: [RFC PATCH 0/5] mm, hugetlb: allocation API and migration improvements Thread-Topic: [RFC PATCH 0/5] mm, hugetlb: allocation API and migration improvements Thread-Index: AQHTdYe6ymCmEtrfoE+9ThtUHNwzSqNLJjoA Date: Wed, 20 Dec 2017 05:33:36 +0000 Message-ID: <95ba8db3-f8aa-528a-db4b-80f9d2ba9d2b@ah.jp.nec.com> References: <20171204140117.7191-1-mhocko@kernel.org> <20171215093309.GU16951@dhcp22.suse.cz> In-Reply-To: <20171215093309.GU16951@dhcp22.suse.cz> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.128.101.10] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3284 Lines: 75 On 12/15/2017 06:33 PM, Michal Hocko wrote: > Naoya, > this has passed Mike's review (thanks for that!), you have mentioned > that you can pass this through your testing machinery earlier. While > I've done some testing already I would really appreciate if you could > do that as well. Review would be highly appreciated as well. Sorry for my slow response. I reviewed/tested this patchset and looks good to me overall. I have one comment on the code path from mbind(2). The callback passed to migrate_pages() in do_mbind() (i.e. new_page()) calls alloc_huge_page_noerr() which currently doesn't call SetPageHugeTemporary(), so hugetlb migration fails when h->surplus_huge_page >= h->nr_overcommit_huge_pages. I don't think this is a bug, but it would be better if mbind(2) works more similarly with other migration callers like move_pages(2)/migrate_pages(2). Thanks, Naoya Horiguchi > > Thanks! > > On Mon 04-12-17 15:01:12, Michal Hocko wrote: >> Hi, >> this is a follow up for [1] for the allocation API and [2] for the >> hugetlb migration. It wasn't really easy to split those into two >> separate patch series as they share some code. >> >> My primary motivation to touch this code is to make the gigantic pages >> migration working. The giga pages allocation code is just too fragile >> and hacked into the hugetlb code now. This series tries to move giga >> pages closer to the first class citizen. We are not there yet but having >> 5 patches is quite a lot already and it will already make the code much >> easier to follow. I will come with other changes on top after this sees >> some review. >> >> The first two patches should be trivial to review. The third patch >> changes the way how we migrate huge pages. Newly allocated pages are a >> subject of the overcommit check and they participate surplus accounting >> which is quite unfortunate as the changelog explains. This patch doesn't >> change anything wrt. giga pages. >> Patch #4 removes the surplus accounting hack from >> __alloc_surplus_huge_page. I hope I didn't miss anything there and a >> deeper review is really due there. >> Patch #5 finally unifies allocation paths and giga pages shouldn't be >> any special anymore. There is also some renaming going on as well. >> >> Shortlog >> Michal Hocko (5): >> mm, hugetlb: unify core page allocation accounting and initialization >> mm, hugetlb: integrate giga hugetlb more naturally to the allocation path >> mm, hugetlb: do not rely on overcommit limit during migration >> mm, hugetlb: get rid of surplus page accounting tricks >> mm, hugetlb: further simplify hugetlb allocation API >> >> Diffstat: >> include/linux/hugetlb.h | 3 + >> mm/hugetlb.c | 305 +++++++++++++++++++++++++++--------------------- >> mm/migrate.c | 3 +- >> 3 files changed, 175 insertions(+), 136 deletions(-) >> >> >> [1] http://lkml.kernel.org/r/20170622193034.28972-1-mhocko@kernel.org >> [2] http://lkml.kernel.org/r/20171122152832.iayefrlxbugphorp@dhcp22.suse.cz >> >> -- >> 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 >