From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAD7FC43144 for ; Wed, 27 Jun 2018 22:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89AFB2499E for ; Wed, 27 Jun 2018 22:59:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89AFB2499E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752051AbeF0W7w (ORCPT ); Wed, 27 Jun 2018 18:59:52 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751668AbeF0W7v (ORCPT ); Wed, 27 Jun 2018 18:59:51 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7C2CA4075647; Wed, 27 Jun 2018 22:59:50 +0000 (UTC) Received: from localhost (ovpn-8-16.pek2.redhat.com [10.72.8.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 50DE62156880; Wed, 27 Jun 2018 22:59:48 +0000 (UTC) Date: Thu, 28 Jun 2018 06:59:45 +0800 From: Baoquan He To: Oscar Salvador Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, pagupta@redhat.com, linux-mm@kvack.org, kirill.shutemov@linux.intel.com Subject: Re: [PATCH v5 2/4] mm/sparsemem: Defer the ms->section_mem_map clearing Message-ID: <20180627225945.GD8970@localhost.localdomain> References: <20180627013116.12411-1-bhe@redhat.com> <20180627013116.12411-3-bhe@redhat.com> <20180627095439.GA5924@techadventures.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180627095439.GA5924@techadventures.net> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 27 Jun 2018 22:59:50 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 27 Jun 2018 22:59:50 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'bhe@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/27/18 at 11:54am, Oscar Salvador wrote: > On Wed, Jun 27, 2018 at 09:31:14AM +0800, Baoquan He wrote: > > In sparse_init(), if CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y, system > > will allocate one continuous memory chunk for mem maps on one node and > > populate the relevant page tables to map memory section one by one. If > > fail to populate for a certain mem section, print warning and its > > ->section_mem_map will be cleared to cancel the marking of being present. > > Like this, the number of mem sections marked as present could become > > less during sparse_init() execution. > > > > Here just defer the ms->section_mem_map clearing if failed to populate > > its page tables until the last for_each_present_section_nr() loop. This > > is in preparation for later optimizing the mem map allocation. > > > > Signed-off-by: Baoquan He > > --- > > mm/sparse-vmemmap.c | 1 - > > mm/sparse.c | 12 ++++++++---- > > 2 files changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c > > index bd0276d5f66b..640e68f8324b 100644 > > --- a/mm/sparse-vmemmap.c > > +++ b/mm/sparse-vmemmap.c > > @@ -303,7 +303,6 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, > > ms = __nr_to_section(pnum); > > pr_err("%s: sparsemem memory map backing failed some memory will not be available\n", > > __func__); > > - ms->section_mem_map = 0; > > Since we are deferring the clearing of section_mem_map, I guess we do not need > > struct mem_section *ms; > ms = __nr_to_section(pnum); > > anymore, right? Right, good catch, thanks. I will post a new round to fix this. > > > } > > > > if (vmemmap_buf_start) { > > diff --git a/mm/sparse.c b/mm/sparse.c > > index 6314303130b0..71ad53da2cd1 100644 > > --- a/mm/sparse.c > > +++ b/mm/sparse.c > > @@ -451,7 +451,6 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, > > ms = __nr_to_section(pnum); > > pr_err("%s: sparsemem memory map backing failed some memory will not be available\n", > > __func__); > > - ms->section_mem_map = 0; > > The same goes here. > > > > -- > Oscar Salvador > SUSE L3