On Fri, Feb 16, 2024 at 04:07:54PM +0900, Byungchul Park wrote:
> For normal numa nodes, node_data[] is initialized at alloc_node_data(),
> but it's not for memoryless node. However, the node *gets onlined* at
> init_cpu_to_node().
>
> Let's look at back free_area_init(). free_area_init_node() will be called
> with node_data[] not set yet, because it's already *onlined*. So
> ->zone_pgdat cannot be initialized properly in the path you mentioned.
I am might be missing something., so bear with me.
free_area_init() gets called before init_cpu_to_node() does.
free_area_init_node() gets called on every possible node.
free_area_init_node then() does
pg_data_t *pgdat = NODE_DATA(nid);,
and then we call free_area_init_core().
free_area_init_core() does
free_area_init_core() does
zone_init_internals()
which ends up doing zone->zone_pgdat = NODE_DATA(nid);
If node_data[] was not set at all, we would already blow up when doing
the first
for_each_node()
pgdat = NODE_DATA(nid);
free_area_init_node(nid);
back in free_area_init().
--
Oscar Salvador
SUSE Labs
