On Tue, Jun 18, 2019 at 08:55:37AM +0800, Wei Yang wrote: > In case of NODE_NOT_IN_PAGE_FLAGS is set, we store section's node id in > section_to_node_table[]. While for hot-add memory, this is missed. > Without this information, page_to_nid() may not give the right node id. > > BTW, current online_pages works because it leverages nid in memory_block. > But the granularity of node id should be mem_section wide. I forgot to ask this before, but why do you mention online_pages here? IMHO, it does not add any value to the changelog, and it does not have much to do with the matter. online_pages() works with memblock granularity and not section granularity. That memblock is just a hot-added range of memory, worth of either 1 section or multiple sections, depending on the arch or on the size of the current memory. And we assume that each hot-added memory all belongs to the same node. > Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> > Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> > Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> > Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > > --- > v2: > * specify the case NODE_NOT_IN_PAGE_FLAGS is effected. > * list one of the victim page_to_nid() > > --- > mm/sparse.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/sparse.c b/mm/sparse.c > index 4012d7f50010..48fa16038cf5 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -733,6 +733,7 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, > */ > page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION); > > + set_section_nid(section_nr, nid); > section_mark_present(ms); > sparse_init_one_section(ms, section_nr, memmap, usemap); > > -- > 2.19.1 > -- Oscar Salvador SUSE L3
