Messages in this thread | | | Date | Fri, 16 Feb 2024 08:52:30 +0100 | From | Oscar Salvador <> | Subject | Re: [PATCH] sched/numa, mm: do not promote folios to nodes not set N_MEMORY |
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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
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