Hi Punit,


On 2018/6/14 1:39, Punit Agrawal wrote:
> Punit Agrawal <punit.agrawal@arm.com> writes:
> 
> 
> [...]
> 
>>
>> CONFIG_HAVE_MEMORYLESS node is not enabled on arm64 which means we end
>> up returning the original node in the fallback path.
>>
>> Xie, does the below patch help? I can submit a proper patch if this
>> fixes the issue for you.
>>
>> -- >8 --
>> Subject: [PATCH] arm64/numa: Enable memoryless numa nodes
>>
>> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
>> ---
>>  arch/arm64/Kconfig   | 4 ++++
>>  arch/arm64/mm/numa.c | 2 ++
>>  2 files changed, 6 insertions(+)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index eb2cf4938f6d..5317e9aa93ab 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -756,6 +756,10 @@ config USE_PERCPU_NUMA_NODE_ID
>>  	def_bool y
>>  	depends on NUMA
>>  
>> +config HAVE_MEMORYLESS_NODES
>> +       def_bool y
>> +       depends on NUMA
>> +
>>  config HAVE_SETUP_PER_CPU_AREA
>>  	def_bool y
>>  	depends on NUMA
>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
>> index dad128ba98bf..c699dcfe93de 100644
>> --- a/arch/arm64/mm/numa.c
>> +++ b/arch/arm64/mm/numa.c
>> @@ -73,6 +73,8 @@ EXPORT_SYMBOL(cpumask_of_node);
>>  static void map_cpu_to_node(unsigned int cpu, int nid)
>>  {
>>  	set_cpu_numa_node(cpu, nid);
>> +	set_numa_mem(local_memory_node(nid));
> 
> Argh, this should be
> 
>         set_cpu_numa_mem(cpu, local_memory_node(nid));
> 
> There is not guarantee that map_cpu_to_node() will be called on the
> local cpu.
> 
> Hanjun, Xie - can you try with the update please?

I've tested this patch, but it does not help.
The boot message is attached.

I tested on a arm board with 128 cores 4 numa nodes, but I set CONFIG_NR_CPUS=72.
Then node 3 is not be created, because node 3 has no memory, and no cpu.
But some pci device may related to node 3, which be set in ACPI table.

165 /* Interface called from ACPI code to setup PCI host controller */
166 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
167 {
168         int node = acpi_get_node(root->device->handle);
169         struct acpi_pci_generic_root_info *ri;
170         struct pci_bus *bus, *child;
171         struct acpi_pci_root_ops *root_ops;
172
            // this node may be not created.
177         ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
178         if (!ri)
179                 return NULL;
180
181         root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
182         if (!root_ops) {
183                 kfree(ri);
184                 return NULL;
185         }
186
187         ri->cfg = pci_acpi_setup_ecam_mapping(root);
188         if (!ri->cfg) {
189                 kfree(ri);
190                 kfree(root_ops);
191                 return NULL;
192         }


> 
> Thanks,
> Punit
> 
>> +
>>  	if (nid >= 0)
>>  		cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
>>  }
> 
> .
> 

-- 
Thanks,
Xie XiuQi