From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 429E86B0005 for ; Thu, 28 Jun 2018 07:19:58 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id t83-v6so3881129wmt.3 for ; Thu, 28 Jun 2018 04:19:58 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id y9-v6sor3203274wrh.46.2018.06.28.04.19.56 for (Google Transport Security); Thu, 28 Jun 2018 04:19:56 -0700 (PDT) Date: Thu, 28 Jun 2018 13:19:54 +0200 From: Oscar Salvador Subject: Re: [PATCH v6 2/5] mm/sparsemem: Defer the ms->section_mem_map clearing Message-ID: <20180628111954.GA12956@techadventures.net> References: <20180628062857.29658-1-bhe@redhat.com> <20180628062857.29658-3-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180628062857.29658-3-bhe@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Baoquan He Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, pagupta@redhat.com, Pavel Tatashin , linux-mm@kvack.org, kirill.shutemov@linux.intel.com On Thu, Jun 28, 2018 at 02:28:54PM +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 > Reviewed-by: Pavel Tatashin Looks good to me. Reviewed-by: Oscar Salvador > --- > mm/sparse-vmemmap.c | 4 ---- > mm/sparse.c | 15 ++++++++------- > 2 files changed, 8 insertions(+), 11 deletions(-) > > diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c > index bd0276d5f66b..68bb65b2d34d 100644 > --- a/mm/sparse-vmemmap.c > +++ b/mm/sparse-vmemmap.c > @@ -292,18 +292,14 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, > } > > for (pnum = pnum_begin; pnum < pnum_end; pnum++) { > - struct mem_section *ms; > - > if (!present_section_nr(pnum)) > continue; > > map_map[pnum] = sparse_mem_map_populate(pnum, nodeid, NULL); > if (map_map[pnum]) > continue; > - 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 6314303130b0..6a706093307d 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -441,17 +441,13 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, > > /* fallback */ > for (pnum = pnum_begin; pnum < pnum_end; pnum++) { > - struct mem_section *ms; > - > if (!present_section_nr(pnum)) > continue; > map_map[pnum] = sparse_mem_map_populate(pnum, nodeid, NULL); > if (map_map[pnum]) > continue; > - 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 */ > @@ -479,7 +475,6 @@ 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 > @@ -583,17 +578,23 @@ 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 > -- Oscar Salvador SUSE L3