queue-5.1/mem-hotplug-fix-node-spanned-pages-when-we-have-a-no.patch

   1 From 02e9affead235d0c14313d33ec565b58256cb28e Mon Sep 17 00:00:00 2001
   2 From: Linxu Fang <fanglinxu@huawei.com>
   3 Date: Mon, 13 May 2019 17:19:17 -0700
   4 Subject: mem-hotplug: fix node spanned pages when we have a node with only
   5  ZONE_MOVABLE
   6
   7 [ Upstream commit 299c83dce9ea3a79bb4b5511d2cb996b6b8e5111 ]
   8
   9 342332e6a925 ("mm/page_alloc.c: introduce kernelcore=mirror option") and
  10 later patches rewrote the calculation of node spanned pages.
  11
  12 e506b99696a2 ("mem-hotplug: fix node spanned pages when we have a movable
  13 node"), but the current code still has problems,
  14
  15 When we have a node with only zone_movable and the node id is not zero,
  16 the size of node spanned pages is double added.
  17
  18 That's because we have an empty normal zone, and zone_start_pfn or
  19 zone_end_pfn is not between arch_zone_lowest_possible_pfn and
  20 arch_zone_highest_possible_pfn, so we need to use clamp to constrain the
  21 range just like the commit <96e907d13602> (bootmem: Reimplement
  22 __absent_pages_in_range() using for_each_mem_pfn_range()).
  23
  24 e.g.
  25 Zone ranges:
  26   DMA      [mem 0x0000000000001000-0x0000000000ffffff]
  27   DMA32    [mem 0x0000000001000000-0x00000000ffffffff]
  28   Normal   [mem 0x0000000100000000-0x000000023fffffff]
  29 Movable zone start for each node
  30   Node 0: 0x0000000100000000
  31   Node 1: 0x0000000140000000
  32 Early memory node ranges
  33   node   0: [mem 0x0000000000001000-0x000000000009efff]
  34   node   0: [mem 0x0000000000100000-0x00000000bffdffff]
  35   node   0: [mem 0x0000000100000000-0x000000013fffffff]
  36   node   1: [mem 0x0000000140000000-0x000000023fffffff]
  37
  38 node 0 DMA      spanned:0xfff   present:0xf9e   absent:0x61
  39 node 0 DMA32    spanned:0xff000 present:0xbefe0 absent:0x40020
  40 node 0 Normal   spanned:0       present:0       absent:0
  41 node 0 Movable  spanned:0x40000 present:0x40000 absent:0
  42 On node 0 totalpages(node_present_pages): 1048446
  43 node_spanned_pages:1310719
  44 node 1 DMA      spanned:0           present:0           absent:0
  45 node 1 DMA32    spanned:0           present:0           absent:0
  46 node 1 Normal   spanned:0x100000    present:0x100000    absent:0
  47 node 1 Movable  spanned:0x100000    present:0x100000    absent:0
  48 On node 1 totalpages(node_present_pages): 2097152
  49 node_spanned_pages:2097152
  50 Memory: 6967796K/12582392K available (16388K kernel code, 3686K rwdata,
  51 4468K rodata, 2160K init, 10444K bss, 5614596K reserved, 0K
  52 cma-reserved)
  53
  54 It shows that the current memory of node 1 is double added.
  55 After this patch, the problem is fixed.
  56
  57 node 0 DMA      spanned:0xfff   present:0xf9e   absent:0x61
  58 node 0 DMA32    spanned:0xff000 present:0xbefe0 absent:0x40020
  59 node 0 Normal   spanned:0       present:0       absent:0
  60 node 0 Movable  spanned:0x40000 present:0x40000 absent:0
  61 On node 0 totalpages(node_present_pages): 1048446
  62 node_spanned_pages:1310719
  63 node 1 DMA      spanned:0           present:0           absent:0
  64 node 1 DMA32    spanned:0           present:0           absent:0
  65 node 1 Normal   spanned:0           present:0           absent:0
  66 node 1 Movable  spanned:0x100000    present:0x100000    absent:0
  67 On node 1 totalpages(node_present_pages): 1048576
  68 node_spanned_pages:1048576
  69 memory: 6967796K/8388088K available (16388K kernel code, 3686K rwdata,
  70 4468K rodata, 2160K init, 10444K bss, 1420292K reserved, 0K
  71 cma-reserved)
  72
  73 Link: http://lkml.kernel.org/r/1554178276-10372-1-git-send-email-fanglinxu@huawei.com
  74 Signed-off-by: Linxu Fang <fanglinxu@huawei.com>
  75 Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
  76 Cc: Xishi Qiu <qiuxishi@huawei.com>
  77 Cc: Michal Hocko <mhocko@suse.com>
  78 Cc: Vlastimil Babka <vbabka@suse.cz>
  79 Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
  80 Cc: Oscar Salvador <osalvador@suse.de>
  81 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  82 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  83 Signed-off-by: Sasha Levin <sashal@kernel.org>
  84 ---
  85  mm/page_alloc.c | 6 ++++--
  86  1 file changed, 4 insertions(+), 2 deletions(-)
  87
  88 diff --git a/mm/page_alloc.c b/mm/page_alloc.c
  89 index c02cff1ed56e..475ca5b1a824 100644
  90 --- a/mm/page_alloc.c
  91 +++ b/mm/page_alloc.c
  92 @@ -6244,13 +6244,15 @@ static unsigned long __init zone_spanned_pages_in_node(int nid,
  93                                         unsigned long *zone_end_pfn,
  94                                         unsigned long *ignored)
  95  {
  96 +       unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
  97 +       unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
  98         /* When hotadd a new node from cpu_up(), the node should be empty */
  99         if (!node_start_pfn && !node_end_pfn)
 100                 return 0;
 101
 102         /* Get the start and end of the zone */
 103 -       *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
 104 -       *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
 105 +       *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
 106 +       *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
 107         adjust_zone_range_for_zone_movable(nid, zone_type,
 108                                 node_start_pfn, node_end_pfn,
 109                                 zone_start_pfn, zone_end_pfn);
 110 --
 111 2.20.1
 112