Vishal Verma <vishal.l.verma@xxxxxxxxx> writes: > In preparation for dax drivers, which can be built as modules, > to use this interface, export it with EXPORT_SYMBOL_GPL(). Add a #else > case for the symbol for builds without CONFIG_MEMORY_HOTPLUG. > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: David Hildenbrand <david@xxxxxxxxxx> > Cc: Oscar Salvador <osalvador@xxxxxxx> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > Cc: Dave Jiang <dave.jiang@xxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Huang Ying <ying.huang@xxxxxxxxx> > Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> > Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> > --- > include/linux/memory_hotplug.h | 5 +++++ > mm/memory_hotplug.c | 1 + > 2 files changed, 6 insertions(+) > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index 013c69753c91..fc5da07ad011 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -355,6 +355,11 @@ extern int arch_create_linear_mapping(int nid, u64 start, u64 size, > struct mhp_params *params); > void arch_remove_linear_mapping(u64 start, u64 size); > extern bool mhp_supports_memmap_on_memory(unsigned long size); > +#else > +static inline bool mhp_supports_memmap_on_memory(unsigned long size) > +{ > + return false; > +} > #endif /* CONFIG_MEMORY_HOTPLUG */ It appears that there is no user of mhp_supports_memmap_on_memory() that may be compiled with !CONFIG_MEMORY_HOTPLUG? -- Best Regards, Huang, Ying > #endif /* __LINUX_MEMORY_HOTPLUG_H */ > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 3f231cf1b410..e9bcacbcbae2 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1284,6 +1284,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size) > IS_ALIGNED(vmemmap_size, PMD_SIZE) && > IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); > } > +EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); > > /* > * NOTE: The caller must call lock_device_hotplug() to serialize hotplug