Only when SPARSEMEM_VMEMMAP is set, memmap returned from
section_activate() points to sub-section page struct. Otherwise, memmap
already points to the whole section page struct.
This means only for SPARSEMEM_VMEMMAP, we need to adjust memmap for
sub-section case.
Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
CC: Dan Williams <dan.j.williams@xxxxxxxxx>
---
mm/sparse.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 586d85662978..b5da121bdd6e 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -886,7 +886,8 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn,
section_mark_present(ms);
/* Align memmap to section boundary in the subsection case */
- if (section_nr_to_pfn(section_nr) != start_pfn)
+ if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) &&
+ section_nr_to_pfn(section_nr) != start_pfn)
memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr));
sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
--
2.17.1
