mm: remove node_start_pfn checking in new WARN_ON for now
Borislav Petkov reports that the new warning added in commit
88fdf75d1bb5 ("mm: warn if pg_data_t isn't initialized with zero")
triggers for him, and it is the node_start_pfn field that has already
been initialized once.
The call trace looks like this:
x86_64_start_kernel ->
x86_64_start_reservations ->
start_kernel ->
setup_arch ->
paging_init ->
zone_sizes_init ->
free_area_init_nodes ->
free_area_init_node
and (with the warning replaced by debug output), Borislav sees
On node 0 totalpages: 4193848
DMA zone: 64 pages used for memmap
DMA zone: 6 pages reserved
DMA zone: 3890 pages, LIFO batch:0
DMA32 zone: 16320 pages used for memmap
DMA32 zone: 798464 pages, LIFO batch:31
Normal zone: 52736 pages used for memmap
Normal zone: 3322368 pages, LIFO batch:31
free_area_init_node: pgdat->node_start_pfn: 4423680 <----
On node 1 totalpages: 4194304
Normal zone: 65536 pages used for memmap
Normal zone: 4128768 pages, LIFO batch:31
free_area_init_node: pgdat->node_start_pfn: 8617984 <----
On node 2 totalpages: 4194304
Normal zone: 65536 pages used for memmap
Normal zone: 4128768 pages, LIFO batch:31
free_area_init_node: pgdat->node_start_pfn: 12812288 <----
On node 3 totalpages: 4194304
Normal zone: 65536 pages used for memmap
Normal zone: 4128768 pages, LIFO batch:31
so remove the bogus warning for now to avoid annoying people. Minchan
Kim is looking at it.
Reported-by: Borislav Petkov <bp@amd64.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 889532b..009ac28 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4511,7 +4511,7 @@
pg_data_t *pgdat = NODE_DATA(nid);
/* pg_data_t should be reset to zero when it's allocated */
- WARN_ON(pgdat->nr_zones || pgdat->node_start_pfn || pgdat->classzone_idx);
+ WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;