On Thu, 27 Mar 2014, Nishanth Aravamudan wrote:

quoted

That looks to be the correct way to handle things. Maybe mark the node as
offline or somehow not present so that the kernel ignores it.

This is a SLUB condition:

mm/slub.c::early_kmem_cache_node_alloc():
...
        page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
...

So the page allocation from the node failed. We have a strange boot
condition where the OS is aware of anode but allocations on that node
fail.

 >         if (page_to_nid(page) != node) {

                printk(KERN_ERR "SLUB: Unable to allocate memory from "
                                "node %d\n", node);
                printk(KERN_ERR "SLUB: Allocating a useless per node structure "
                                "in order to be able to continue\n");
        }
...

Since this is quite early, and we have not set up the nodemasks yet,
does it make sense to perhaps have a temporary init-time nodemask that
we set bits in here, and "fix-up" those nodes when we setup the
nodemasks?

Please take care of this earlier than this. The page allocator in general
should allow allocations from all nodes with memory during boot,