From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 80CA86B0358 for ; Wed, 6 Dec 2017 03:03:08 -0500 (EST) Received: by mail-wr0-f199.google.com with SMTP id h12so1579167wre.12 for ; Wed, 06 Dec 2017 00:03:08 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id a8si98567edn.479.2017.12.06.00.03.06 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 06 Dec 2017 00:03:06 -0800 (PST) Date: Wed, 6 Dec 2017 09:03:05 +0100 From: Michal Hocko Subject: Re: [mmotm] mm/page_owner: align with pageblock_nr_pages Message-ID: <20171206080305.GA16386@dhcp22.suse.cz> References: <1512395284-13588-1-git-send-email-zhongjiang@huawei.com> <20171205165826.aed52f6b6e5ca4cd7994ce31@linux-foundation.org> <5A275987.3070001@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5A275987.3070001@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: zhong jiang Cc: Andrew Morton , vbabka@suse.cz, linux-mm@kvack.org On Wed 06-12-17 10:44:23, zhong jiang wrote: > On 2017/12/6 8:58, Andrew Morton wrote: > > On Mon, 4 Dec 2017 21:48:04 +0800 zhong jiang wrote: > > > >> Currently, init_pages_in_zone walk the zone in pageblock_nr_pages > >> steps. MAX_ORDER_NR_PAGES is possible to have holes when > >> CONFIG_HOLES_IN_ZONE is set. it is likely to be different between > >> MAX_ORDER_NR_PAGES and pageblock_nr_pages. if we skip the size of > >> MAX_ORDER_NR_PAGES, it will result in the second 2M memroy leak. > >> > >> meanwhile, the change will make the code consistent. because the > >> entire function is based on the pageblock_nr_pages steps. > >> > >> ... > >> > >> --- a/mm/page_owner.c > >> +++ b/mm/page_owner.c > >> @@ -527,7 +527,7 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) > >> */ > >> for (; pfn < end_pfn; ) { > >> if (!pfn_valid(pfn)) { > >> - pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); > >> + pfn = ALIGN(pfn + 1, pageblock_nr_pages); > >> continue; > >> } > > I *think* Michal and Vlastimil will be OK with this as-newly-presented. > > Guys, can you please have another think? > According to Vlastimil's comment, it is not simple as it looks to cover all corners. > Maybe architecture need explicit define the hole granularity to use correctly. > so far, I have no a good idea to solve it perfectly. > Anyway. I will go further to find out. Yes please! The thing is clear as mud right now and doing cosmetic changes without further clarification doesn't help to improve the situation much. -- Michal Hocko SUSE Labs -- 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