4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> 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-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1057,7 +1057,7 @@ 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; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html