[PATCH] x86_64: reenable support for system without on node0

From: Yinghai Lu
Date: Sun Feb 17 2008 - 04:54:22 EST



one system doesn't have RAM for node0 installed.

SRAT: PXM 0 -> APIC 0 -> Node 0
SRAT: PXM 0 -> APIC 1 -> Node 0
SRAT: PXM 1 -> APIC 2 -> Node 1
SRAT: PXM 1 -> APIC 3 -> Node 1
SRAT: Node 1 PXM 1 0-a0000
SRAT: Node 1 PXM 1 0-dd000000
SRAT: Node 1 PXM 1 0-123000000
ACPI: SLIT: nodes = 2
10 13
13 10
mapped APIC to ffffffffff5fb000 ( fee00000)
Bootmem setup node 1 0000000000000000-0000000123000000
NODE_DATA [000000000000e000 - 0000000000014fff]
bootmap [0000000000015000 - 00000000000395ff] pages 25
Could not find start_pfn for node 0
Pid: 0, comm: swapper Not tainted 2.6.24-smp-g5a514e21-dirty #14

Call Trace:
[<ffffffff80bab498>] free_area_init_node+0x22/0x381
[<ffffffff8045ffc5>] generic_swap+0x0/0x17
[<ffffffff80bab0cc>] find_zone_movable_pfns_for_nodes+0x54/0x271
[<ffffffff80baba5f>] free_area_init_nodes+0x239/0x287
[<ffffffff80ba6311>] paging_init+0x46/0x4c
[<ffffffff80b9dda5>] setup_arch+0x3c3/0x44e
[<ffffffff80b978be>] start_kernel+0x6f/0x2c7
[<ffffffff80b971cc>] _sinittext+0x1cc/0x1d3

the
Could not find start_pfn for node 0
should not there, because node 0 is not online.

in mm/page_alloc.c

/*
* Array of node states.
*/
nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
[N_POSSIBLE] = NODE_MASK_ALL,
[N_ONLINE] = { { [0] = 1UL } },
#ifndef CONFIG_NUMA
[N_NORMAL_MEMORY] = { { [0] = 1UL } },
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = { { [0] = 1UL } },
#endif
[N_CPU] = { { [0] = 1UL } },
#endif /* NUMA */
};
EXPORT_SYMBOL(node_states);

this patch will clear node_online_map at first.

Signed-off-by: Yinghai Lu <yinghai.lu@xxxxxxx>

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 1aecc65..59898fb 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -494,11 +494,13 @@ void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
int i;

nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);

#ifdef CONFIG_NUMA_EMU
if (cmdline && !numa_emulation(start_pfn, end_pfn))
return;
nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
#endif

#ifdef CONFIG_ACPI_NUMA
@@ -506,6 +508,7 @@ void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
end_pfn << PAGE_SHIFT))
return;
nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
#endif

#ifdef CONFIG_K8_NUMA
@@ -513,6 +516,7 @@ void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
end_pfn<<PAGE_SHIFT))
return;
nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
#endif
printk(KERN_INFO "%s\n",
numa_off ? "NUMA turned off" : "No NUMA configuration found");
@@ -524,7 +528,6 @@ void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
memnode_shift = 63;
memnodemap = memnode.embedded_map;
memnodemap[0] = 0;
- nodes_clear(node_online_map);
node_set_online(0);
node_set(0, node_possible_map);
for (i = 0; i < NR_CPUS; i++)
--
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