"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> writes:
> If the new NUMA node onlined doesn't have a performance level assigned,
> the kernel adds the NUMA node to default memory tier.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
> ---
> include/linux/memory-tiers.h | 1 +
> mm/memory-tiers.c | 75 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 76 insertions(+)
>
> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
> index ef380a39db3a..3d5f14d57ae6 100644
> --- a/include/linux/memory-tiers.h
> +++ b/include/linux/memory-tiers.h
> @@ -14,6 +14,7 @@
> #define MEMTIER_PERF_LEVEL_DRAM (1 << (MEMTIER_CHUNK_BITS + 2))
> /* leave one tier below this slow pmem */
> #define MEMTIER_PERF_LEVEL_PMEM (1 << MEMTIER_CHUNK_BITS)
> +#define MEMTIER_HOTPLUG_PRIO 100
>
> extern bool numa_demotion_enabled;
>
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index 41a21cc5ae55..cc3a47ec18e4 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -5,6 +5,7 @@
> #include <linux/lockdep.h>
> #include <linux/moduleparam.h>
> #include <linux/node.h>
> +#include <linux/memory.h>
> #include <linux/memory-tiers.h>
>
> struct memory_tier {
> @@ -64,6 +65,78 @@ static struct memory_tier *find_create_memory_tier(unsigned int perf_level)
> return new_memtier;
> }
>
> +static struct memory_tier *__node_get_memory_tier(int node)
> +{
> + struct memory_tier *memtier;
> +
> + list_for_each_entry(memtier, &memory_tiers, list) {
> + if (node_isset(node, memtier->nodelist))
> + return memtier;
> + }
> + return NULL;
> +}
> +
> +static void init_node_memory_tier(int node)
set_node_memory_tier()?
> +{
> + int perf_level;
> + struct memory_tier *memtier;
> +
> + mutex_lock(&memory_tier_lock);
> +
> + memtier = __node_get_memory_tier(node);
> + if (!memtier) {
> + perf_level = node_devices[node]->perf_level;
> + memtier = find_create_memory_tier(perf_level);
> + node_set(node, memtier->nodelist);
> + }
> + mutex_unlock(&memory_tier_lock);
> +}
> +
> +static void clear_node_memory_tier(int node)
> +{
> + struct memory_tier *memtier;
> +
> + mutex_lock(&memory_tier_lock);
> + memtier = __node_get_memory_tier(node);
> + if (memtier)
> + node_clear(node, memtier->nodelist);
When memtier->nodelist becomes empty, we need to free memtier?
> + mutex_unlock(&memory_tier_lock);
> +}
> +
> +/*
> + * This runs whether reclaim-based migration is enabled or not,
> + * which ensures that the user can turn reclaim-based migration
> + * at any time without needing to recalculate migration targets.
> + */
The comments doesn't apply here.
> +static int __meminit migrate_on_reclaim_callback(struct notifier_block *self,
> + unsigned long action, void *_arg)
Now we are building memory tiers instead of working on demotion. So I
think we should rename the function to memtier_hotplug_callback().
> +{
> + struct memory_notify *arg = _arg;
> +
> + /*
> + * Only update the node migration order when a node is
> + * changing status, like online->offline.
> + */
> + if (arg->status_change_nid < 0)
> + return notifier_from_errno(0);
> +
> + switch (action) {
> + case MEM_OFFLINE:
> + clear_node_memory_tier(arg->status_change_nid);
> + break;
> + case MEM_ONLINE:
> + init_node_memory_tier(arg->status_change_nid);
> + break;
> + }
> +
> + return notifier_from_errno(0);
> +}
> +
> +static void __init migrate_on_reclaim_init(void)
> +{
> + hotplug_memory_notifier(migrate_on_reclaim_callback, MEMTIER_HOTPLUG_PRIO);
> +}
I suggest to call hotplug_memory_notifier() in memory_tier_init()
directly. We are not working on demotion here.
> +
> static int __init memory_tier_init(void)
> {
> int node;
> @@ -96,6 +169,8 @@ static int __init memory_tier_init(void)
> node_property->perf_level = default_memtier_perf_level;
> }
> mutex_unlock(&memory_tier_lock);
> +
> + migrate_on_reclaim_init();
> return 0;
> }
> subsys_initcall(memory_tier_init);
Best Regards,
Huang, Ying
