On Mon, May 16, 2022 at 06:22:08PM +0800, Muchun Song wrote: > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -913,6 +913,13 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, > ms = __nr_to_section(section_nr); > set_section_nid(section_nr, nid); > __section_mark_present(ms, section_nr); > + /* > + * Mark whole section as non-optimizable once there is a subsection > + * whose vmemmap pages are allocated from alternative allocator. The > + * early section is always optimizable. > + */ > + if (!early_section(ms) && altmap) > + section_mark_cannot_optimize_vmemmap(ms); Because no one expects those sections to be removed? IIRC, early_section + altmap only happened in case of sub-section pmem scenario? I guess my question is: can we really have early_sections coming from alternative allocator? I think this should be spelled out more. -- Oscar Salvador SUSE Labs
