4.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mel Gorman <mgor...@techsingularity.net>
commit e4568d3803852d00effd41dcdd489e726b998879 upstream.
early_pfn_to_nid can return node 0 if a PFN is invalid on machines that
has no node 0. A machine with only node 1 was observed to crash with
the following message:
BUG: unable to handle kernel paging request at 000000000002a3c8
PGD 0
Modules linked in:
Hardware name: Supermicro H8DSP-8/H8DSP-8, BIOS 080011 06/30/2006
task: ffffffff81c0d500 ti: ffffffff81c00000 task.ti: ffffffff81c00000
RIP: reserve_bootmem_region+0x6a/0xef
CR2: 000000000002a3c8 CR3: 0000000001c06000 CR4: 00000000000006b0
Call Trace:
free_all_bootmem+0x4b/0x12a
mem_init+0x70/0xa3
start_kernel+0x25b/0x49b
The problem is that early_page_uninitialised uses the early_pfn_to_nid
helper which returns node 0 for invalid PFNs. No caller of
early_pfn_to_nid cares except early_page_uninitialised. This patch has
early_pfn_to_nid always return a valid node.
Link:
http://lkml.kernel.org/r/1468008031-3848-3-git-send-email-mgor...@techsingularity.net
Signed-off-by: Mel Gorman <mgor...@techsingularity.net>
Acked-by: David Rientjes <rient...@google.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1110,7 +1110,7 @@ int __meminit early_pfn_to_nid(unsigned
spin_lock(&early_pfn_lock);
nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
if (nid < 0)
- nid = 0;
+ nid = first_online_node;
spin_unlock(&early_pfn_lock);
return nid;
