mm/demotion: update node_is_toptier to work with memory tiers

With memory tier 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(slower) memory tiers added we consider all
memory tiers above a memory tier having CPU NUMA nodes as a top memory
tier

Link: https://lkml.kernel.org/r/20220818131042.113280-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Wei Xu <weixugc@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hesham Almatary <hesham.almatary@huawei.com>
Cc: Jagdish Gediya <jvgediya.oss@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index 42791554b9b97e386c7c4769b06d880c4d5b7af4..965009aa01d72b73c66d046a0ff4816e376e852b 100644 (file)
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -40,6 +40,7 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype);
 #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)
 {
@@ -50,6 +51,11 @@ 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
@@ -87,5 +93,10 @@ 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 40d641a8bfb0d4cfba3cc232f6f837458f7e5c76..9ec680dd607f7515d0692ba65f7b69e8d12dd30c 100644 (file)
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -185,9 +185,4 @@ 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 83c47a989260999ae173e0b6c7eaa3886aba04b8..b387dbc74e7be3b5b14390f668932d0b860c40b5 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -36,6 +36,7 @@
 #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 dad86dd3ec9617ee25502a6a49d964e8f40ca5b5..ba844fe9cc8c551ccdf6eb87886c13023d5e3407 100644 (file)
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -32,6 +32,7 @@ static LIST_HEAD(memory_tiers);
 static struct memory_dev_type *node_memory_types[MAX_NUMNODES];
 static struct memory_dev_type *default_dram_type;
 #ifdef CONFIG_MIGRATION
+static int top_tier_adistance;
 /*
  * node_demotion[] examples:
  *
@@ -157,6 +158,31 @@ 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->adistance_start < top_tier_adistance)
+               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;
@@ -314,6 +340,26 @@ static void establish_demotion_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) {
+               tier_nodes = get_memtier_nodemask(memtier);
+               nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
+               if (!nodes_empty(tier_nodes)) {
+                       /*
+                        * abstract distance below the max value of this memtier
+                        * is considered toptier.
+                        */
+                       top_tier_adistance = memtier->adistance_start + MEMTIER_CHUNK_SIZE;
+                       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 2a2329bf7c1a3f27a8f6bf0d81e281f11d45ee46..d74573c36573b45f68404ffc6d93bc2fbebe0cad 100644 (file)
--- 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 ed013f836b4a53414d06b7d22d4541d230b99441..55ed4a889990fb4effd6ca044d966e39c68c76bc 100644 (file)
--- 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>