"Ho-Ren (Jack) Chuang" <horenchu...@bytedance.com> writes: [snip]
> @@ -655,6 +672,34 @@ void mt_put_memory_types(struct list_head *memory_types) > } > EXPORT_SYMBOL_GPL(mt_put_memory_types); > > +/* > + * This is invoked via `late_initcall()` to initialize memory tiers for > + * CPU-less memory nodes after driver initialization, which is > + * expected to provide `adistance` algorithms. > + */ > +static int __init memory_tier_late_init(void) > +{ > + int nid; > + > + mutex_lock(&memory_tier_lock); > + for_each_node_state(nid, N_MEMORY) > + if (!node_state(nid, N_CPU) && > + node_memory_types[nid].memtype == NULL) Think about this again. It seems that it is better to check "node_memory_types[nid].memtype == NULL" only here. Because for all node with N_CPU in memory_tier_init(), "node_memory_types[nid].memtype" will be !NULL. And it's possible (in theory) that some nodes becomes "node_state(nid, N_CPU) == true" between memory_tier_init() and memory_tier_late_init(). Otherwise, Looks good to me. Feel free to add Reviewed-by: "Huang, Ying" <ying.hu...@intel.com> in the future version. > + /* > + * Some device drivers may have initialized memory tiers > + * between `memory_tier_init()` and > `memory_tier_late_init()`, > + * potentially bringing online memory nodes and > + * configuring memory tiers. Exclude them here. > + */ > + set_node_memory_tier(nid); > + > + establish_demotion_targets(); > + mutex_unlock(&memory_tier_lock); > + > + return 0; > +} > +late_initcall(memory_tier_late_init); > + [snip] -- Best Regards, Huang, Ying