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@xxxxxxxxxx> > > Signed-off-by: Jia He <justin.he@xxxxxxx> > > --- > > 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 ... > -- > Michal Hocko > SUSE Labs -- Sincerely yours, Mike.