[PATCH] powerpc/numa: Fix percpu allocations to be NUMA aware

[Michael Ellerman]

Balbir Singh <bsingharora at gmail.com> writes:
> On Fri, Jun 2, 2017 at 3:14 PM, Michael Ellerman <mpe at ellerman.id.au> wrote:
>> diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
>> index 8b3b46b7b0f2..8f3b2ec09b9e 100644
>> --- a/arch/powerpc/include/asm/topology.h
>> +++ b/arch/powerpc/include/asm/topology.h
>> @@ -44,8 +44,22 @@ extern void __init dump_numa_cpu_topology(void);
>>  extern int sysfs_add_device_to_node(struct device *dev, int nid);
>>  extern void sysfs_remove_device_from_node(struct device *dev, int nid);
>>
>> +static inline int early_cpu_to_node(int cpu)
>> +{
>> +       int nid;
>> +
>> +       nid = numa_cpu_lookup_table[cpu];
>> +
>> +       /*
>> +        * Some functions, eg. node_distance() don't cope with -1, so instead
>> +        * fall back to node 0 if nid is unset (it should be, except bugs).
>> +        */
>> +       return (nid < 0) ? 0 : nid;
>> +}
>>  #else
>
> Not sure if its entirely related, but I had tried to do
>
> https://patchwork.ozlabs.org/patch/683556/
>
> to setup the mapping earlier, but we would have still missed the pcpu_fc_alloc.

It's related. But doesn't fix this bug.

I didn't merge it because I assumed it wouldn't build with
CONFIG_NUMA=n, but seems it does so I'll grab it.

cheers