The patch titled
Subject: mem-hotplug: fix node spanned pages when we have a node with only zone_movable
has been added to the -mm tree. Its filename is
mem-hotplug-fix-node-spanned-pages-when-we-have-a-node-with-only-zone_movable.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mem-hotplug-fix-node-spanned-pages-when-we-have-a-node-with-only-zone_movable.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mem-hotplug-fix-node-spanned-pages-when-we-have-a-node-with-only-zone_movable.patch
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------------------------------------------------------
From: Linxu Fang <fanglinxu@xxxxxxxxxx>
Subject: mem-hotplug: fix node spanned pages when we have a node with only zone_movable
commit <342332e6a925> ("mm/page_alloc.c: introduce kernelcore=mirror
option") and series patches rewrote the calculation of node spanned
pages.
commit <e506b99696a2> (mem-hotplug: fix node spanned pages when we have a
movable node), but the current code still has problems,
when we have a node with only zone_movable and the node id is not zero,
the size of node spanned pages is double added.
That's because we have an empty normal zone, and zone_start_pfn or
zone_end_pfn is not between arch_zone_lowest_possible_pfn and
arch_zone_highest_possible_pfn, so we need to use clamp to constrain the
range just like the commit <96e907d13602> (bootmem: Reimplement
__absent_pages_in_range() using for_each_mem_pfn_range()).
e.g.
Zone ranges:
DMA [mem 0x0000000000001000-0x0000000000ffffff]
DMA32 [mem 0x0000000001000000-0x00000000ffffffff]
Normal [mem 0x0000000100000000-0x000000023fffffff]
Movable zone start for each node
Node 0: 0x0000000100000000
Node 1: 0x0000000140000000
Early memory node ranges
node 0: [mem 0x0000000000001000-0x000000000009efff]
node 0: [mem 0x0000000000100000-0x00000000bffdffff]
node 0: [mem 0x0000000100000000-0x000000013fffffff]
node 1: [mem 0x0000000140000000-0x000000023fffffff]
node 0 DMA spanned:0xfff present:0xf9e absent:0x61
node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020
node 0 Normal spanned:0 present:0 absent:0
node 0 Movable spanned:0x40000 present:0x40000 absent:0
On node 0 totalpages(node_present_pages): 1048446
node_spanned_pages:1310719
node 1 DMA spanned:0 present:0 absent:0
node 1 DMA32 spanned:0 present:0 absent:0
node 1 Normal spanned:0x100000 present:0x100000 absent:0
node 1 Movable spanned:0x100000 present:0x100000 absent:0
On node 1 totalpages(node_present_pages): 2097152
node_spanned_pages:2097152
Memory: 6967796K/12582392K available (16388K kernel code, 3686K rwdata,
4468K rodata, 2160K init, 10444K bss, 5614596K reserved, 0K
cma-reserved)
It shows that the current memory of node 1 is double added.
After this patch, the problem is fixed.
node 0 DMA spanned:0xfff present:0xf9e absent:0x61
node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020
node 0 Normal spanned:0 present:0 absent:0
node 0 Movable spanned:0x40000 present:0x40000 absent:0
On node 0 totalpages(node_present_pages): 1048446
node_spanned_pages:1310719
node 1 DMA spanned:0 present:0 absent:0
node 1 DMA32 spanned:0 present:0 absent:0
node 1 Normal spanned:0 present:0 absent:0
node 1 Movable spanned:0x100000 present:0x100000 absent:0
On node 1 totalpages(node_present_pages): 1048576
node_spanned_pages:1048576
memory: 6967796K/8388088K available (16388K kernel code, 3686K rwdata,
4468K rodata, 2160K init, 10444K bss, 1420292K reserved, 0K
cma-reserved)
Link: http://lkml.kernel.org/r/1554178276-10372-1-git-send-email-fanglinxu@xxxxxxxxxx
Signed-off-by: Linxu Fang <fanglinxu@xxxxxxxxxx>
Cc: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/page_alloc.c~mem-hotplug-fix-node-spanned-pages-when-we-have-a-node-with-only-zone_movable
+++ a/mm/page_alloc.c
@@ -6241,13 +6241,15 @@ static unsigned long __init zone_spanned
unsigned long *zone_end_pfn,
unsigned long *ignored)
{
+ unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
+ unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
/* When hotadd a new node from cpu_up(), the node should be empty */
if (!node_start_pfn && !node_end_pfn)
return 0;
/* Get the start and end of the zone */
- *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
- *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
+ *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
+ *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
adjust_zone_range_for_zone_movable(nid, zone_type,
node_start_pfn, node_end_pfn,
zone_start_pfn, zone_end_pfn);
_
Patches currently in -mm which might be from fanglinxu@xxxxxxxxxx are
mem-hotplug-fix-node-spanned-pages-when-we-have-a-node-with-only-zone_movable.patch
