Re: [Qemu-devel] [PATCH 3/7] spapr: Refactor spapr_populate_memory()

[Nishanth Aravamudan]

On 16.06.2014 [17:53:49 +1000], Alexey Kardashevskiy wrote:
> Current QEMU does not support memoryless NUMA nodes.
> This prepares SPAPR for that.
> 
> This moves 2 calls of spapr_populate_memory_node() into
> the existing loop which handles nodes other than than
> the first one.
> 
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
>  hw/ppc/spapr.c | 31 +++++++++++--------------------
>  1 file changed, 11 insertions(+), 20 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index cb3a10a..666b676 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -689,28 +689,13 @@ static void spapr_populate_memory_node(void *fdt, int 
> nodeid, hwaddr start,
> 
>  static int spapr_populate_memory(sPAPREnvironment *spapr, void *fdt)
>  {
> -    hwaddr node0_size, mem_start, node_size;
> +    hwaddr mem_start, node_size;
>      int i;
> 
> -    /* memory node(s) */
> -    if (nb_numa_nodes > 1 && node_mem[0] < ram_size) {
> -        node0_size = node_mem[0];
> -    } else {
> -        node0_size = ram_size;
> -    }
> -
> -    /* RMA */
> -    spapr_populate_memory_node(fdt, 0, 0, spapr->rma_size);
> -
> -    /* RAM: Node 0 */
> -    if (node0_size > spapr->rma_size) {
> -        spapr_populate_memory_node(fdt, 0, spapr->rma_size,
> -                                   node0_size - spapr->rma_size);
> -    }
> -
> -    /* RAM: Node 1 and beyond */
> -    mem_start = node0_size;
> -    for (i = 1; i < nb_numa_nodes; i++) {
> +    for (i = 0, mem_start = 0; i < nb_numa_nodes; ++i) {
> +        if (!node_mem[i]) {
> +            continue;
> +        }

Doesn't this skip memoryless nodes? What actually puts the memoryless
node in the device-tree?

And if you were to put them in, wouldn't spapr_populate_memory_node()
fail because we'd be creating two nodes with address@hidden where XXX is the
same (starting address) for both?

Thanks,
Nish