From: David Rientjes When we are in the emulated NUMA case, we need to make sure that all existing apicid_to_node mappings that point to real node ID's now point to the equivalent fake node ID's. If we simply iterate over all apicid_to_node[] members for each node, we risk remapping an entry if it shares a node ID with a real node. Since apicid's may not be consecutive, we're forced to create an automatic array of apicid_to_node mappings and then copy it over once we have finished remapping fake to real nodes. Cc: Andi Kleen Signed-off-by: David Rientjes Signed-off-by: Andrew Morton --- arch/x86_64/mm/srat.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff -puN arch/x86_64/mm/srat.c~x86_64-numa-fake-apicid_to_node-mapping-for-fake-numa-2 arch/x86_64/mm/srat.c --- a/arch/x86_64/mm/srat.c~x86_64-numa-fake-apicid_to_node-mapping-for-fake-numa-2 +++ a/arch/x86_64/mm/srat.c @@ -470,10 +470,13 @@ static int __init find_node_by_addr(unsi */ void __init acpi_fake_nodes(const struct bootnode *fake_nodes, int num_nodes) { - int i; + int i, j; int fake_node_to_pxm_map[MAX_NUMNODES] = { [0 ... MAX_NUMNODES-1] = PXM_INVAL }; + unsigned char fake_apicid_to_node[MAX_LOCAL_APIC] = { + [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE + }; printk(KERN_INFO "Faking PXM affinity for fake nodes on real " "topology.\n"); @@ -487,9 +490,17 @@ void __init acpi_fake_nodes(const struct if (pxm == PXM_INVAL) continue; fake_node_to_pxm_map[i] = pxm; + /* + * For each apicid_to_node mapping that exists for this real + * node, it must now point to the fake node ID. + */ + for (j = 0; j < MAX_LOCAL_APIC; j++) + if (apicid_to_node[j] == nid) + fake_apicid_to_node[j] = i; } for (i = 0; i < num_nodes; i++) __acpi_map_pxm_to_node(fake_node_to_pxm_map[i], i); + memcpy(apicid_to_node, fake_apicid_to_node, sizeof(apicid_to_node)); nodes_clear(nodes_parsed); for (i = 0; i < num_nodes; i++) _