On Mon, Jun 16, 2014 at 05:11:40PM -0300, Eduardo Habkost wrote: [...] > Wait, is the node ID visible to the guest at all? I believe it is a > QEMU-internal thing, just to allow the NUMA nodes to be ordered in the > command-line. I would even claim that the parameter is useless and > shouldn't have been introduced in the first place. > > What I don't se is: why you need the command-line to look like: > -numa node,id=1,mem=X > when you can simply write it as: > -numa node,id=0 -numa node,id=1,mem=X
Oh, I believe now I see it: the problem is not that you don't just need "memory-less nodes" (which could be simply defined explicitly like above), but that you need non-contiguous node IDs, which are visible to the guest. In this case, my example above with two -numa options would work, but it would be confusing as the user just wants one node with ID=1 (instead of two nodes). So, now your patch makes sense to me. But we first need something to make sure the following command-line: -numa node,id=3 -numa node,id=2 be different from: -numa node,id=0 -numa node,id=1 -numa node,id=2 -numa node,id=3 The former should divide the memory in half, between nodes 1 and 2. The latter should divide the memory in four, between nodes 0, 1, and 2. -- Eduardo