From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f197.google.com (mail-qt0-f197.google.com [209.85.216.197]) by kanga.kvack.org (Postfix) with ESMTP id 727576B0007 for ; Mon, 21 May 2018 06:16:13 -0400 (EDT) Received: by mail-qt0-f197.google.com with SMTP id x30-v6so14459837qtm.20 for ; Mon, 21 May 2018 03:16:13 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id m126-v6si699170qkd.147.2018.05.21.03.16.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 May 2018 03:16:12 -0700 (PDT) From: Baoquan He Subject: [PATCH v4 2/4] mm/sparsemem: Defer the ms->section_mem_map clearing Date: Mon, 21 May 2018 18:15:53 +0800 Message-Id: <20180521101555.25610-3-bhe@redhat.com> In-Reply-To: <20180521101555.25610-1-bhe@redhat.com> References: <20180521101555.25610-1-bhe@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: 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, Baoquan He 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; } if (vmemmap_buf_start) { diff --git a/mm/sparse.c b/mm/sparse.c index 48cf7b7982e2..3d697292be08 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -453,7 +453,6 @@ 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; } } #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ @@ -481,7 +480,6 @@ static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum) pr_err("%s: sparsemem memory map backing failed some memory will not be available\n", __func__); - ms->section_mem_map = 0; return NULL; } #endif @@ -585,17 +583,23 @@ void __init sparse_init(void) #endif for_each_present_section_nr(0, pnum) { + struct mem_section *ms; + ms = __nr_to_section(pnum); usemap = usemap_map[pnum]; - if (!usemap) + if (!usemap) { + ms->section_mem_map = 0; continue; + } #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER map = map_map[pnum]; #else map = sparse_early_mem_map_alloc(pnum); #endif - if (!map) + if (!map) { + ms->section_mem_map = 0; continue; + } sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap); -- 2.13.6