"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> writes:
> With memory tiers support we can have memory only NUMA nodes
> in the top tier from which we want to avoid promotion tracking NUMA
> faults. Update node_is_toptier to work with memory tiers.
> All NUMA nodes are by default top tier nodes. With lower memory
> tiers added we consider all memory tiers above a memory tier having
> CPU NUMA nodes as a top memory tier
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
> ---
> include/linux/memory-tiers.h | 11 +++++++++
> include/linux/node.h | 5 -----
> mm/huge_memory.c | 1 +
> mm/memory-tiers.c | 43 ++++++++++++++++++++++++++++++++++++
> mm/migrate.c | 1 +
> mm/mprotect.c | 1 +
> 6 files changed, 57 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
> index 0e58588fa066..085dd815bf73 100644
> --- a/include/linux/memory-tiers.h
> +++ b/include/linux/memory-tiers.h
> @@ -20,6 +20,7 @@ extern bool numa_demotion_enabled;
> #ifdef CONFIG_MIGRATION
> int next_demotion_node(int node);
> void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
> +bool node_is_toptier(int node);
> #else
> static inline int next_demotion_node(int node)
> {
> @@ -30,6 +31,11 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
> {
> *targets = NODE_MASK_NONE;
> }
> +
> +static inline bool node_is_toptier(int node)
> +{
> + return true;
> +}
> #endif
>
> #else
> @@ -44,5 +50,10 @@ static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *target
> {
> *targets = NODE_MASK_NONE;
> }
> +
> +static inline bool node_is_toptier(int node)
> +{
> + return true;
> +}
> #endif /* CONFIG_NUMA */
> #endif /* _LINUX_MEMORY_TIERS_H */
> diff --git a/include/linux/node.h b/include/linux/node.h
> index a2a16d4104fd..d0432db18094 100644
> --- a/include/linux/node.h
> +++ b/include/linux/node.h
> @@ -191,9 +191,4 @@ static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
>
> #define to_node(device) container_of(device, struct node, dev)
>
> -static inline bool node_is_toptier(int node)
> -{
> - return node_state(node, N_CPU);
> -}
> -
> #endif /* _LINUX_NODE_H_ */
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 834f288b3769..8405662646e9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -35,6 +35,7 @@
> #include <linux/numa.h>
> #include <linux/page_owner.h>
> #include <linux/sched/sysctl.h>
> +#include <linux/memory-tiers.h>
>
> #include <asm/tlb.h>
> #include <asm/pgalloc.h>
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index 4a96e4213d66..f0515bfd4051 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -13,6 +13,7 @@
>
> struct memory_tier {
> struct list_head list;
> + int id;
> int perf_level;
> nodemask_t nodelist;
> nodemask_t lower_tier_mask;
> @@ -26,6 +27,7 @@ static LIST_HEAD(memory_tiers);
> static DEFINE_MUTEX(memory_tier_lock);
>
> #ifdef CONFIG_MIGRATION
> +static int top_tier_id;
> /*
> * node_demotion[] examples:
> *
> @@ -129,6 +131,7 @@ static struct memory_tier *find_create_memory_tier(unsigned int perf_level)
> if (!new_memtier)
> return ERR_PTR(-ENOMEM);
>
> + new_memtier->id = perf_level >> MEMTIER_CHUNK_BITS;
> new_memtier->perf_level = perf_level;
> if (found_slot)
> list_add_tail(&new_memtier->list, ent);
> @@ -154,6 +157,31 @@ static struct memory_tier *__node_get_memory_tier(int node)
> }
>
> #ifdef CONFIG_MIGRATION
> +bool node_is_toptier(int node)
> +{
> + bool toptier;
> + pg_data_t *pgdat;
> + struct memory_tier *memtier;
> +
> + pgdat = NODE_DATA(node);
> + if (!pgdat)
> + return false;
> +
> + rcu_read_lock();
> + memtier = rcu_dereference(pgdat->memtier);
> + if (!memtier) {
> + toptier = true;
> + goto out;
> + }
> + if (memtier->id >= top_tier_id)
> + toptier = true;
> + else
> + toptier = false;
> +out:
> + rcu_read_unlock();
> + return toptier;
> +}
> +
> void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
> {
> struct memory_tier *memtier;
> @@ -304,6 +332,21 @@ static void establish_migration_targets(void)
> }
> } while (1);
> }
> + /*
> + * Promotion is allowed from a memory tier to higher
> + * memory tier only if the memory tier doesn't include
> + * compute. We want to skip promotion from a memory tier,
> + * if any node that is part of the memory tier have CPUs.
> + * Once we detect such a memory tier, we consider that tier
> + * as top tiper from which promotion is not allowed.
> + */
> + list_for_each_entry_reverse(memtier, &memory_tiers, list) {
> + nodes_and(used, node_states[N_CPU], memtier->nodelist);
> + if (!nodes_empty(used)) {
> + top_tier_id = memtier->id;
I don't think we need to introduce memory tier ID for this. We can add
a top_tier_perf_level, set it here and use it in node_is_toptier().
Best Regards,
Huang, Ying
> + break;
> + }
> + }
> /*
> * Now build the lower_tier mask for each node collecting node mask from
> * all memory tier below it. This allows us to fallback demotion page
> diff --git a/mm/migrate.c b/mm/migrate.c
> index c758c9c21d7d..1da81136eaaa 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -50,6 +50,7 @@
> #include <linux/memory.h>
> #include <linux/random.h>
> #include <linux/sched/sysctl.h>
> +#include <linux/memory-tiers.h>
>
> #include <asm/tlbflush.h>
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index ba5592655ee3..92a2fc0fa88b 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -31,6 +31,7 @@
> #include <linux/pgtable.h>
> #include <linux/sched/sysctl.h>
> #include <linux/userfaultfd_k.h>
> +#include <linux/memory-tiers.h>
> #include <asm/cacheflush.h>
> #include <asm/mmu_context.h>
> #include <asm/tlbflush.h>
