[PATCH 4.19 092/118] Revert "x86/e820: put !E820_TYPE_RAM regions into memblock.reserved"

From: Greg Kroah-Hartman
Date: Tue Dec 11 2018 - 10:57:45 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit 9fd61bc95130d4971568b89c9548b5e0a4e18e0e ]

commit 124049decbb1 ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved") breaks movable_node kernel option because it changed
the memory gap range to reserved memblock. So, the node is marked as
Normal zone even if the SRAT has Hot pluggable affinity.

=====================================================================
kernel: BIOS-e820: [mem 0x0000180000000000-0x0000180fffffffff] usable
kernel: BIOS-e820: [mem 0x00001c0000000000-0x00001c0fffffffff] usable
...
kernel: reserved[0x12]#011[0x0000181000000000-0x00001bffffffffff], 0x000003f000000000 bytes flags: 0x0
...
kernel: ACPI: SRAT: Node 2 PXM 6 [mem 0x180000000000-0x1bffffffffff] hotplug
kernel: ACPI: SRAT: Node 3 PXM 7 [mem 0x1c0000000000-0x1fffffffffff] hotplug
...
kernel: Movable zone start for each node
kernel: Node 3: 0x00001c0000000000
kernel: Early memory node ranges
...
=====================================================================

The original issue is fixed by the former patches, so let's revert commit
124049decbb1 ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved").

Link: http://lkml.kernel.org/r/20181002143821.5112-4-msys.mizuma@xxxxxxxxx
Signed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kernel/e820.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index c88c23c658c1..d1f25c831447 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1248,7 +1248,6 @@ void __init e820__memblock_setup(void)
{
int i;
u64 end;
- u64 addr = 0;

/*
* The bootstrap memblock region count maximum is 128 entries
@@ -1265,21 +1264,13 @@ void __init e820__memblock_setup(void)
struct e820_entry *entry = &e820_table->entries[i];

end = entry->addr + entry->size;
- if (addr < entry->addr)
- memblock_reserve(addr, entry->addr - addr);
- addr = end;
if (end != (resource_size_t)end)
continue;

- /*
- * all !E820_TYPE_RAM ranges (including gap ranges) are put
- * into memblock.reserved to make sure that struct pages in
- * such regions are not left uninitialized after bootup.
- */
if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
- memblock_reserve(entry->addr, entry->size);
- else
- memblock_add(entry->addr, entry->size);
+ continue;
+
+ memblock_add(entry->addr, entry->size);
}

/* Throw away partial pages: */
--
2.19.1