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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 5075AC43142 for ; Wed, 27 Jun 2018 01:48:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1C8D26944 for ; Wed, 27 Jun 2018 01:48:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1C8D26944 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 S1754597AbeF0BsD (ORCPT ); Tue, 26 Jun 2018 21:48:03 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43098 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753213AbeF0BsC (ORCPT ); Tue, 26 Jun 2018 21:48:02 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 84A9081A8E54; Wed, 27 Jun 2018 01:48:01 +0000 (UTC) Received: from localhost (ovpn-8-24.pek2.redhat.com [10.72.8.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8880B1C66B; Wed, 27 Jun 2018 01:48:00 +0000 (UTC) Date: Wed, 27 Jun 2018 09:47:57 +0800 From: Baoquan He To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, pagupta@redhat.com Cc: linux-mm@kvack.org, kirill.shutemov@linux.intel.com Subject: Re: [PATCH v5 0/4] mm/sparse: Optimize memmap allocation during sparse_init() Message-ID: <20180627014757.GC8970@localhost.localdomain> References: <20180627013116.12411-1-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180627013116.12411-1-bhe@redhat.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 27 Jun 2018 01:48:01 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 27 Jun 2018 01:48:01 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.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 09:31am, Baoquan He wrote: > This is v4 post. V3 can be found here: > https://lkml.org/lkml/2018/2/27/928 Sorry, forgot updating this part. This is v5 post, v4 can be found here: http://lkml.kernel.org/r/20180521101555.25610-1-bhe@redhat.com > > V1 can be found here: > https://www.spinics.net/lists/linux-mm/msg144486.html > > In sparse_init(), two temporary pointer arrays, usemap_map and map_map > are allocated with the size of NR_MEM_SECTIONS. They are used to store > each memory section's usemap and mem map if marked as present. In > 5-level paging mode, this will cost 512M memory though they will be > released at the end of sparse_init(). System with few memory, like > kdump kernel which usually only has about 256M, will fail to boot > because of allocation failure if CONFIG_X86_5LEVEL=y. > > In this patchset, optimize the memmap allocation code to only use > usemap_map and map_map with the size of nr_present_sections. This > makes kdump kernel boot up with normal crashkernel='' setting when > CONFIG_X86_5LEVEL=y. > > Change log: > v4->v5: > Improve patch 3/4 log according to Dave's suggestion. > > Correct the wrong copy&paste of making 'nr_consumed_maps' to > 'alloc_usemap_and_memmap' mistakenly which is pointed out by > Dave in patch 4/4 code comment. > > Otherwise, no code change in this version. > v3->v4: > Improve according to Dave's three concerns which are in patch 0004: > > Rename variable 'idx_present' to 'nr_consumed_maps' which used to > index the memmap and usemap of present sections. > > Add a check if 'nr_consumed_maps' goes beyond nr_present_sections. > > Add code comment above the final for_each_present_section_nr() to > tell why 'nr_consumed_maps' need be increased in each iteration > whether the 'ms->section_mem_map' need cleared or out. > > v2->v3: > Change nr_present_sections as __initdata and add code comment > according to Andrew's suggestion. > > Change the local variable 'i' as idx_present which loops over the > present sections, and improve the code. These are suggested by > Dave and Pankaj. > > Add a new patch 0003 which adds a new parameter 'data_unit_size' > to function alloc_usemap_and_memmap() in which we will update 'data' > to make it point at new position. However its type 'void *' can't give > us needed info to do that. Need pass the unit size in. So change code > in patch 0004 accordingly. This is a code bug fix found when tested > the memory deployed on multiple nodes. > > v1-v2: > Split out the nr_present_sections adding as a single patch for easier > reviewing. > > Rewrite patch log according to Dave's suggestion. > > Fix code bug in patch 0002 reported by test robot. > > Baoquan He (4): > mm/sparse: Add a static variable nr_present_sections > mm/sparsemem: Defer the ms->section_mem_map clearing > mm/sparse: Add a new parameter 'data_unit_size' for > alloc_usemap_and_memmap > mm/sparse: Optimize memmap allocation during sparse_init() > > mm/sparse-vmemmap.c | 6 ++--- > mm/sparse.c | 72 +++++++++++++++++++++++++++++++++++++++++------------ > 2 files changed, 59 insertions(+), 19 deletions(-) > > -- > 2.13.6 >