Re: [PATCH] net: Avoid allocing memory on memoryless numa node

From: Jakub Kicinski
Date: Sun Oct 11 2020 - 15:18:07 EST


On Sun, 11 Oct 2020 12:11:40 +0800 Xianting Tian wrote:
> In architecture like powerpc, we can have cpus without any local memory
> attached to it. In such cases the node does not have real memory.
>
> Use local_memory_node(), which is guaranteed to have memory.
> local_memory_node is a noop in other architectures that does not support
> memoryless nodes.
>
> Signed-off-by: Xianting Tian <tian.xianting@xxxxxxx>
> ---
> net/core/dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 266073e30..dcb4533ef 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2590,7 +2590,7 @@ static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
> new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
> else
> new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
> - cpu_to_node(attr_index));
> + local_memory_node(cpu_to_node(attr_index)));
> if (!new_map)
> return NULL;
>

Are we going to patch all kmalloc_node() callers now to apply
local_memory_node()? Can't the allocator take care of this?