"Ho-Ren (Jack) Chuang" <horenchuang@xxxxxxxxxxxxx> 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.huang@xxxxxxxxx>
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
