Let's update the pfn manually whenever we continue the loop. This makes
the code easier to read but also less error prone (and we can directly
fix one issue).
When overlap_memmap_init() returns true, pfn is updated to
"memblock_region_memory_end_pfn(r)". So it already points at the *next*
pfn to process. Incrementing the pfn another time is wrong, we might
leave one uninitialized. I spotted this by inspecting the code, so I have
no idea if this is relevant in practise (with kernelcore=mirror).
Fixes: a9a9e77fbf27 ("mm: move mirrored memory specific code outside of memmap_init_zone")
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/page_alloc.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a41bd7341de1..a92791512077 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5905,18 +5905,20 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
}
#endif
- for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ for (pfn = start_pfn; pfn < end_pfn; ) {
/*
* There can be holes in boot-time mem_map[]s handed to this
* function. They do not exist on hotplugged memory.
*/
if (context == MEMMAP_EARLY) {
if (!early_pfn_valid(pfn)) {
- pfn = next_pfn(pfn) - 1;
+ pfn = next_pfn(pfn);
continue;
}
- if (!early_pfn_in_nid(pfn, nid))
+ if (!early_pfn_in_nid(pfn, nid)) {
+ pfn++;
continue;
+ }
if (overlap_memmap_init(zone, &pfn))
continue;
if (defer_init(nid, pfn, end_pfn))
@@ -5944,6 +5946,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
cond_resched();
}
+ pfn++;
}
}
--
2.24.1
