Re: [Qemu-devel] [PATCH v4 1/1] numa: equally distribute memory on nodes

[Eduardo Habkost]

On Tue, May 02, 2017 at 06:29:55PM +0200, Laurent Vivier wrote:
[...]
> diff --git a/numa.c b/numa.c
> index 6fc2393..750fd95 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -294,6 +294,42 @@ static void validate_numa_cpus(void)
>      g_free(seen_cpus);
>  }
>  
> +void numa_legacy_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
> +                                 int nb_nodes, ram_addr_t size)
> +{
> +    int i;
> +    uint64_t usedmem = 0;
> +
> +    /* Align each node according to the alignment
> +     * requirements of the machine class
> +     */
> +
> +    for (i = 0; i < nb_nodes - 1; i++) {
> +        nodes[i].node_mem = (size / nb_nodes) &
> +                            ~((1 << mc->numa_mem_align_shift) - 1);
> +        usedmem += nodes[i].node_mem;
> +    }
> +    nodes[i].node_mem = size - usedmem;
> +}
> +
> +void numa_default_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
> +                                  int nb_nodes, ram_addr_t size)
> +{
> +    int i;
> +    uint64_t usedmem = 0, node_mem;
> +    uint64_t granularity = size / nb_nodes;
> +    uint64_t propagate = 0;
> +
> +    for (i = 0; i < nb_nodes - 1; i++) {
> +        node_mem = (granularity + propagate) &
> +                   ~((1 << mc->numa_mem_align_shift) - 1);
> +        propagate = granularity + propagate - node_mem;
> +        nodes[i].node_mem = node_mem;
> +        usedmem += node_mem;
> +    }
> +    nodes[i].node_mem = ram_size - usedmem;

I believe you meant 'size - usedmem' here.

I can fix this while applying the patch, if that's OK. The rest
of the patch looks good to me.

> +}
> +
>  void parse_numa_opts(MachineClass *mc)
>  {
>      int i;
> @@ -336,17 +372,8 @@ void parse_numa_opts(MachineClass *mc)
>              }
>          }
>          if (i == nb_numa_nodes) {
> -            uint64_t usedmem = 0;
> -
> -            /* Align each node according to the alignment
> -             * requirements of the machine class
> -             */
> -            for (i = 0; i < nb_numa_nodes - 1; i++) {
> -                numa_info[i].node_mem = (ram_size / nb_numa_nodes) &
> -                                        ~((1 << mc->numa_mem_align_shift) - 
> 1);
> -                usedmem += numa_info[i].node_mem;
> -            }
> -            numa_info[i].node_mem = ram_size - usedmem;
> +            assert(mc->numa_auto_assign_ram);
> +            mc->numa_auto_assign_ram(mc, numa_info, nb_numa_nodes, ram_size);
>          }
>  
>          numa_total = 0;
> -- 
> 2.9.3
> 

-- 
Eduardo