Re: [PATCH v2 1/3] arm64/numa: export memory_add_physaddr_to_nid as EXPORT_SYMBOL_GPL

David Hildenbrand
2020-07-07T12:26:41Z

On 07.07.20 14:13, Mike Rapoport wrote:
> On Tue, Jul 07, 2020 at 01:54:54PM +0200, Michal Hocko wrote:
>> On Tue 07-07-20 13:59:15, Jia He wrote:
>>> This exports memory_add_physaddr_to_nid() for module driver to use.
>>>
>>> memory_add_physaddr_to_nid() is a fallback option to get the nid in case
>>> NUMA_NO_NID is detected.
>>>
>>> Suggested-by: David Hildenbrand <david@redhat.com>
>>> Signed-off-by: Jia He <justin.he@arm.com>
>>> ---
>>> arch/arm64/mm/numa.c | 5 +++--
>>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
>>> index aafcee3e3f7e..7eeb31740248 100644
>>> --- a/arch/arm64/mm/numa.c
>>> +++ b/arch/arm64/mm/numa.c
>>> @@ -464,10 +464,11 @@ void __init arm64_numa_init(void)
>>>
>>> /*
>>> * We hope that we will be hotplugging memory on nodes we already know about,
>>> - * such that acpi_get_node() succeeds and we never fall back to this...
>>> + * such that acpi_get_node() succeeds. But when SRAT is not present, the node
>>> + * id may be probed as NUMA_NO_NODE by acpi, Here provide a fallback option.
>>> */
>>> int memory_add_physaddr_to_nid(u64 addr)
>>> {
>>> - pr_warn("Unknown node for memory at 0x%llx, assuming node 0\n", addr);
>>> return 0;
>>> }
>>> +EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>>
>> Does it make sense to export a noop function? Wouldn't make more sense
>> to simply make it static inline somewhere in a header? I haven't checked
>> whether there is an easy way to do that sanely bu this just hit my eyes.
>
> We'll need to either add a CONFIG_ option or arch specific callback to
> make both non-empty (x86, powerpc, ia64) and empty (arm64, sh)
> implementations coexist ...

Note: I have a similar dummy (return 0) patch for s390x lying around here.

--
Thanks,

David / dhildenb