Re: [PATCH 1/2] arm64: avoid alloc memory on offline node

[Hanjun Guo <guohanjun@xxxxxxxxxx>]

Hi Punit,

On 2018/6/14 1:39, Punit Agrawal wrote:
> Punit Agrawal <punit.agrawal@xxxxxxx> 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@xxxxxxx>
>> ---
>>  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?

Thanks for looking into this, we will try this tomorrow
(the hardware is occupied now) and update here.

Thanks
Hanjun