| Date | Fri, 11 Jul 2014 10:13:57 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [RFC Patch V1 07/30] mm: Use cpu_to_mem()/numa_mem_id() to support memoryless node |
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On Fri, 11 Jul 2014, Tejun Heo wrote:
> Hello, > > On Fri, Jul 11, 2014 at 03:37:24PM +0800, Jiang Liu wrote: > > When CONFIG_HAVE_MEMORYLESS_NODES is enabled, cpu_to_node()/numa_node_id() > > may return a node without memory, and later cause system failure/panic > > when calling kmalloc_node() and friends with returned node id. > > The patch itself looks okay to me but is this the right way to handle > this? Can't we just let the allocators fall back to the nearest node > with memory? Why do we need to impose this awareness of memory-less > node on all the users?
Allocators typically fall back but they wont in some cases if you say that you want memory from a particular node. A GFP_THISNODE would force a failure of the alloc. In other cases it should fall back. I am not sure that all allocations obey these conventions though.
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