| Message ID | 20220728190436.858458-6-aneesh.kumar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/demotion: Memory tiers and demotion | expand |
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > This patch switch the demotion target building logic to use memory tiers > instead of NUMA distance. All N_MEMORY NUMA nodes will be placed in the > default memory tier and additional memory tiers will be added by drivers like > dax kmem. > > This patch builds the demotion target for a NUMA node by looking at all > memory tiers below the tier to which the NUMA node belongs. The closest node > in the immediately following memory tier is used as a demotion target. > > Since we are now only building demotion target for N_MEMORY NUMA nodes > the CPU hotplug calls are removed in this patch. > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > --- > include/linux/memory-tiers.h | 13 ++ > include/linux/migrate.h | 13 -- > mm/memory-tiers.c | 221 +++++++++++++++++++- > mm/migrate.c | 394 ----------------------------------- > mm/vmstat.c | 4 - > 5 files changed, 233 insertions(+), 412 deletions(-) > > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > index 4f4baf0bf430..e56a57c6ef78 100644 > --- a/include/linux/memory-tiers.h > +++ b/include/linux/memory-tiers.h > @@ -31,6 +31,14 @@ struct memory_dev_type { > #ifdef CONFIG_NUMA > extern bool numa_demotion_enabled; > struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *default_type); > +#ifdef CONFIG_MIGRATION > +int next_demotion_node(int node); > +#else > +static inline int next_demotion_node(int node) > +{ > + return NUMA_NO_NODE; > +} > +#endif > > #else > > @@ -39,5 +47,10 @@ static inline struct memory_dev_type *init_node_memory_type(int node, struct mem > { > return ERR_PTR(-EINVAL); > } > + > +static inline int next_demotion_node(int node) > +{ > + return NUMA_NO_NODE; > +} > #endif /* CONFIG_NUMA */ > #endif /* _LINUX_MEMORY_TIERS_H */ > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > index 43e737215f33..93fab62e6548 100644 > --- a/include/linux/migrate.h > +++ b/include/linux/migrate.h > @@ -75,19 +75,6 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, > > #endif /* CONFIG_MIGRATION */ > > -#if defined(CONFIG_MIGRATION) && defined(CONFIG_NUMA) > -extern void set_migration_target_nodes(void); > -extern void migrate_on_reclaim_init(void); > -extern int next_demotion_node(int node); > -#else > -static inline void set_migration_target_nodes(void) {} > -static inline void migrate_on_reclaim_init(void) {} > -static inline int next_demotion_node(int node) > -{ > - return NUMA_NO_NODE; > -} > -#endif > - > #ifdef CONFIG_COMPACTION > extern int PageMovable(struct page *page); > extern void __SetPageMovable(struct page *page, struct address_space *mapping); > diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c > index 109be75fa554..60845aa74afc 100644 > --- a/mm/memory-tiers.c > +++ b/mm/memory-tiers.c > @@ -2,8 +2,11 @@ > #include <linux/slab.h> > #include <linux/lockdep.h> > #include <linux/memory.h> > +#include <linux/random.h> > #include <linux/memory-tiers.h> > > +#include "internal.h" > + > struct memory_tier { > /* hierarchy of memory tiers */ > struct list_head list; > @@ -17,9 +20,74 @@ struct memory_tier { > int adistance_start; > }; > > +struct demotion_nodes { > + nodemask_t preferred; > +}; > + > static DEFINE_MUTEX(memory_tier_lock); > static LIST_HEAD(memory_tiers); > struct memory_dev_type *node_memory_types[MAX_NUMNODES]; > +#ifdef CONFIG_MIGRATION > +/* > + * node_demotion[] examples: > + * > + * Example 1: > + * > + * Node 0 & 1 are CPU + DRAM nodes, node 2 & 3 are PMEM nodes. > + * > + * node distances: > + * node 0 1 2 3 > + * 0 10 20 30 40 > + * 1 20 10 40 30 > + * 2 30 40 10 40 > + * 3 40 30 40 10 > + * > + * memory_tiers0 = 0-1 > + * memory_tiers1 = 2-3 > + * > + * node_demotion[0].preferred = 2 > + * node_demotion[1].preferred = 3 > + * node_demotion[2].preferred = <empty> > + * node_demotion[3].preferred = <empty> > + * > + * Example 2: > + * > + * Node 0 & 1 are CPU + DRAM nodes, node 2 is memory-only DRAM node. > + * > + * node distances: > + * node 0 1 2 > + * 0 10 20 30 > + * 1 20 10 30 > + * 2 30 30 10 > + * > + * memory_tiers0 = 0-2 > + * > + * node_demotion[0].preferred = <empty> > + * node_demotion[1].preferred = <empty> > + * node_demotion[2].preferred = <empty> > + * > + * Example 3: > + * > + * Node 0 is CPU + DRAM nodes, Node 1 is HBM node, node 2 is PMEM node. > + * > + * node distances: > + * node 0 1 2 > + * 0 10 20 30 > + * 1 20 10 40 > + * 2 30 40 10 > + * > + * memory_tiers0 = 1 > + * memory_tiers1 = 0 > + * memory_tiers2 = 2 > + * > + * node_demotion[0].preferred = 2 > + * node_demotion[1].preferred = 0 > + * node_demotion[2].preferred = <empty> > + * > + */ > +static struct demotion_nodes *node_demotion __read_mostly; > +#endif /* CONFIG_MIGRATION */ > + > /* > * For now let's have 4 memory tier below default DRAM tier. > */ > @@ -82,6 +150,144 @@ static struct memory_tier *__node_get_memory_tier(int node) > return NULL; > } > > +#ifdef CONFIG_MIGRATION > +/** > + * next_demotion_node() - Get the next node in the demotion path > + * @node: The starting node to lookup the next node > + * > + * Return: node id for next memory node in the demotion path hierarchy > + * from @node; NUMA_NO_NODE if @node is terminal. This does not keep > + * @node online or guarantee that it *continues* to be the next demotion > + * target. > + */ > +int next_demotion_node(int node) > +{ > + struct demotion_nodes *nd; > + int target; > + > + if (!node_demotion) > + return NUMA_NO_NODE; > + > + nd = &node_demotion[node]; > + > + /* > + * node_demotion[] is updated without excluding this > + * function from running. > + * > + * Make sure to use RCU over entire code blocks if > + * node_demotion[] reads need to be consistent. > + */ > + rcu_read_lock(); > + /* > + * If there are multiple target nodes, just select one > + * target node randomly. > + * > + * In addition, we can also use round-robin to select > + * target node, but we should introduce another variable > + * for node_demotion[] to record last selected target node, > + * that may cause cache ping-pong due to the changing of > + * last target node. Or introducing per-cpu data to avoid > + * caching issue, which seems more complicated. So selecting > + * target node randomly seems better until now. > + */ > + target = node_random(&nd->preferred); Don't find code to optimize node_random() for weight == 1 case, forget to do that? Best Regards, Huang, Ying > + rcu_read_unlock(); > + > + return target; > +} > + > +static void disable_all_demotion_targets(void) > +{ > + int node; > + > + for_each_node_state(node, N_MEMORY) > + node_demotion[node].preferred = NODE_MASK_NONE; > + /* > + * Ensure that the "disable" is visible across the system. > + * Readers will see either a combination of before+disable > + * state or disable+after. They will never see before and > + * after state together. > + */ > + synchronize_rcu(); > +} > + > +static __always_inline nodemask_t get_memtier_nodemask(struct memory_tier *memtier) > +{ > + nodemask_t nodes = NODE_MASK_NONE; > + struct memory_dev_type *memtype; > + > + list_for_each_entry(memtype, &memtier->memory_types, tier_sibiling) > + nodes_or(nodes, nodes, memtype->nodes); > + > + return nodes; > +} > + > +/* > + * Find an automatic demotion target for all memory > + * nodes. Failing here is OK. It might just indicate > + * being at the end of a chain. > + */ > +static void establish_demotion_targets(void) > +{ > + struct memory_tier *memtier; > + struct demotion_nodes *nd; > + int target = NUMA_NO_NODE, node; > + int distance, best_distance; > + nodemask_t tier_nodes; > + > + lockdep_assert_held_once(&memory_tier_lock); > + > + if (!node_demotion || !IS_ENABLED(CONFIG_MIGRATION)) > + return; > + > + disable_all_demotion_targets(); > + > + for_each_node_state(node, N_MEMORY) { > + best_distance = -1; > + nd = &node_demotion[node]; > + > + memtier = __node_get_memory_tier(node); > + if (!memtier || list_is_first(&memtier->list, &memory_tiers)) > + continue; > + /* > + * Get the lower memtier to find the demotion node list. > + */ > + memtier = list_prev_entry(memtier, list); > + tier_nodes = get_memtier_nodemask(memtier); > + /* > + * find_next_best_node, use 'used' nodemask as a skip list. > + * Add all memory nodes except the selected memory tier > + * nodelist to skip list so that we find the best node from the > + * memtier nodelist. > + */ > + nodes_andnot(tier_nodes, node_states[N_MEMORY], tier_nodes); > + > + /* > + * Find all the nodes in the memory tier node list of same best distance. > + * add them to the preferred mask. We randomly select between nodes > + * in the preferred mask when allocating pages during demotion. > + */ > + do { > + target = find_next_best_node(node, &tier_nodes); > + if (target == NUMA_NO_NODE) > + break; > + > + distance = node_distance(node, target); > + if (distance == best_distance || best_distance == -1) { > + best_distance = distance; > + node_set(target, nd->preferred); > + } else { > + break; > + } > + } while (1); > + } > +} > + > +#else > +static inline void disable_all_demotion_targets(void) {} > +static inline void establish_demotion_targets(void) {} > +#endif /* CONFIG_MIGRATION */ > + > static void init_node_memory_tier(int node) > { > struct memory_tier *memtier; > @@ -89,6 +295,13 @@ static void init_node_memory_tier(int node) > mutex_lock(&memory_tier_lock); > > memtier = __node_get_memory_tier(node); > + /* > + * if node is already part of the tier proceed with the > + * current tier value, because we might want to establish > + * new migration paths now. The node might be added to a tier > + * before it was made part of N_MEMORY, hence estabilish_demotion_targets > + * will have skipped this node. > + */ > if (!memtier) { > struct memory_dev_type *memtype; > > @@ -99,6 +312,7 @@ static void init_node_memory_tier(int node) > memtype = node_memory_types[node]; > memtier = find_create_memory_tier(memtype); > } > + establish_demotion_targets(); > mutex_unlock(&memory_tier_lock); > } > > @@ -125,6 +339,7 @@ static void clear_node_memory_tier(int node) > if (list_empty(¤t_memtier->memory_types)) > destroy_memory_tier(current_memtier); > } > + establish_demotion_targets(); > } > mutex_unlock(&memory_tier_lock); > } > @@ -182,7 +397,11 @@ static int __init memory_tier_init(void) > panic("%s() failed to register memory tier: %ld\n", > __func__, PTR_ERR(memtier)); > mutex_unlock(&memory_tier_lock); > - > +#ifdef CONFIG_MIGRATION > + node_demotion = kcalloc(MAX_NUMNODES, sizeof(struct demotion_nodes), > + GFP_KERNEL); > + WARN_ON(!node_demotion); > +#endif > hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRIO); > return 0; > } > diff --git a/mm/migrate.c b/mm/migrate.c > index fce7d4a9e940..c758c9c21d7d 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2117,398 +2117,4 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, > return 0; > } > #endif /* CONFIG_NUMA_BALANCING */ > - > -/* > - * node_demotion[] example: > - * > - * Consider a system with two sockets. Each socket has > - * three classes of memory attached: fast, medium and slow. > - * Each memory class is placed in its own NUMA node. The > - * CPUs are placed in the node with the "fast" memory. The > - * 6 NUMA nodes (0-5) might be split among the sockets like > - * this: > - * > - * Socket A: 0, 1, 2 > - * Socket B: 3, 4, 5 > - * > - * When Node 0 fills up, its memory should be migrated to > - * Node 1. When Node 1 fills up, it should be migrated to > - * Node 2. The migration path start on the nodes with the > - * processors (since allocations default to this node) and > - * fast memory, progress through medium and end with the > - * slow memory: > - * > - * 0 -> 1 -> 2 -> stop > - * 3 -> 4 -> 5 -> stop > - * > - * This is represented in the node_demotion[] like this: > - * > - * { nr=1, nodes[0]=1 }, // Node 0 migrates to 1 > - * { nr=1, nodes[0]=2 }, // Node 1 migrates to 2 > - * { nr=0, nodes[0]=-1 }, // Node 2 does not migrate > - * { nr=1, nodes[0]=4 }, // Node 3 migrates to 4 > - * { nr=1, nodes[0]=5 }, // Node 4 migrates to 5 > - * { nr=0, nodes[0]=-1 }, // Node 5 does not migrate > - * > - * Moreover some systems may have multiple slow memory nodes. > - * Suppose a system has one socket with 3 memory nodes, node 0 > - * is fast memory type, and node 1/2 both are slow memory > - * type, and the distance between fast memory node and slow > - * memory node is same. So the migration path should be: > - * > - * 0 -> 1/2 -> stop > - * > - * This is represented in the node_demotion[] like this: > - * { nr=2, {nodes[0]=1, nodes[1]=2} }, // Node 0 migrates to node 1 and node 2 > - * { nr=0, nodes[0]=-1, }, // Node 1 dose not migrate > - * { nr=0, nodes[0]=-1, }, // Node 2 does not migrate > - */ > - > -/* > - * Writes to this array occur without locking. Cycles are > - * not allowed: Node X demotes to Y which demotes to X... > - * > - * If multiple reads are performed, a single rcu_read_lock() > - * must be held over all reads to ensure that no cycles are > - * observed. > - */ > -#define DEFAULT_DEMOTION_TARGET_NODES 15 > - > -#if MAX_NUMNODES < DEFAULT_DEMOTION_TARGET_NODES > -#define DEMOTION_TARGET_NODES (MAX_NUMNODES - 1) > -#else > -#define DEMOTION_TARGET_NODES DEFAULT_DEMOTION_TARGET_NODES > -#endif > - > -struct demotion_nodes { > - unsigned short nr; > - short nodes[DEMOTION_TARGET_NODES]; > -}; > - > -static struct demotion_nodes *node_demotion __read_mostly; > - > -/** > - * next_demotion_node() - Get the next node in the demotion path > - * @node: The starting node to lookup the next node > - * > - * Return: node id for next memory node in the demotion path hierarchy > - * from @node; NUMA_NO_NODE if @node is terminal. This does not keep > - * @node online or guarantee that it *continues* to be the next demotion > - * target. > - */ > -int next_demotion_node(int node) > -{ > - struct demotion_nodes *nd; > - unsigned short target_nr, index; > - int target; > - > - if (!node_demotion) > - return NUMA_NO_NODE; > - > - nd = &node_demotion[node]; > - > - /* > - * node_demotion[] is updated without excluding this > - * function from running. RCU doesn't provide any > - * compiler barriers, so the READ_ONCE() is required > - * to avoid compiler reordering or read merging. > - * > - * Make sure to use RCU over entire code blocks if > - * node_demotion[] reads need to be consistent. > - */ > - rcu_read_lock(); > - target_nr = READ_ONCE(nd->nr); > - > - switch (target_nr) { > - case 0: > - target = NUMA_NO_NODE; > - goto out; > - case 1: > - index = 0; > - break; > - default: > - /* > - * If there are multiple target nodes, just select one > - * target node randomly. > - * > - * In addition, we can also use round-robin to select > - * target node, but we should introduce another variable > - * for node_demotion[] to record last selected target node, > - * that may cause cache ping-pong due to the changing of > - * last target node. Or introducing per-cpu data to avoid > - * caching issue, which seems more complicated. So selecting > - * target node randomly seems better until now. > - */ > - index = get_random_int() % target_nr; > - break; > - } > - > - target = READ_ONCE(nd->nodes[index]); > - > -out: > - rcu_read_unlock(); > - return target; > -} > - > -/* Disable reclaim-based migration. */ > -static void __disable_all_migrate_targets(void) > -{ > - int node, i; > - > - if (!node_demotion) > - return; > - > - for_each_online_node(node) { > - node_demotion[node].nr = 0; > - for (i = 0; i < DEMOTION_TARGET_NODES; i++) > - node_demotion[node].nodes[i] = NUMA_NO_NODE; > - } > -} > - > -static void disable_all_migrate_targets(void) > -{ > - __disable_all_migrate_targets(); > - > - /* > - * Ensure that the "disable" is visible across the system. > - * Readers will see either a combination of before+disable > - * state or disable+after. They will never see before and > - * after state together. > - * > - * The before+after state together might have cycles and > - * could cause readers to do things like loop until this > - * function finishes. This ensures they can only see a > - * single "bad" read and would, for instance, only loop > - * once. > - */ > - synchronize_rcu(); > -} > - > -/* > - * Find an automatic demotion target for 'node'. > - * Failing here is OK. It might just indicate > - * being at the end of a chain. > - */ > -static int establish_migrate_target(int node, nodemask_t *used, > - int best_distance) > -{ > - int migration_target, index, val; > - struct demotion_nodes *nd; > - > - if (!node_demotion) > - return NUMA_NO_NODE; > - > - nd = &node_demotion[node]; > - > - migration_target = find_next_best_node(node, used); > - if (migration_target == NUMA_NO_NODE) > - return NUMA_NO_NODE; > - > - /* > - * If the node has been set a migration target node before, > - * which means it's the best distance between them. Still > - * check if this node can be demoted to other target nodes > - * if they have a same best distance. > - */ > - if (best_distance != -1) { > - val = node_distance(node, migration_target); > - if (val > best_distance) > - goto out_clear; > - } > - > - index = nd->nr; > - if (WARN_ONCE(index >= DEMOTION_TARGET_NODES, > - "Exceeds maximum demotion target nodes\n")) > - goto out_clear; > - > - nd->nodes[index] = migration_target; > - nd->nr++; > - > - return migration_target; > -out_clear: > - node_clear(migration_target, *used); > - return NUMA_NO_NODE; > -} > - > -/* > - * When memory fills up on a node, memory contents can be > - * automatically migrated to another node instead of > - * discarded at reclaim. > - * > - * Establish a "migration path" which will start at nodes > - * with CPUs and will follow the priorities used to build the > - * page allocator zonelists. > - * > - * The difference here is that cycles must be avoided. If > - * node0 migrates to node1, then neither node1, nor anything > - * node1 migrates to can migrate to node0. Also one node can > - * be migrated to multiple nodes if the target nodes all have > - * a same best-distance against the source node. > - * > - * This function can run simultaneously with readers of > - * node_demotion[]. However, it can not run simultaneously > - * with itself. Exclusion is provided by memory hotplug events > - * being single-threaded. > - */ > -static void __set_migration_target_nodes(void) > -{ > - nodemask_t next_pass; > - nodemask_t this_pass; > - nodemask_t used_targets = NODE_MASK_NONE; > - int node, best_distance; > - > - /* > - * Avoid any oddities like cycles that could occur > - * from changes in the topology. This will leave > - * a momentary gap when migration is disabled. > - */ > - disable_all_migrate_targets(); > - > - /* > - * Allocations go close to CPUs, first. Assume that > - * the migration path starts at the nodes with CPUs. > - */ > - next_pass = node_states[N_CPU]; > -again: > - this_pass = next_pass; > - next_pass = NODE_MASK_NONE; > - /* > - * To avoid cycles in the migration "graph", ensure > - * that migration sources are not future targets by > - * setting them in 'used_targets'. Do this only > - * once per pass so that multiple source nodes can > - * share a target node. > - * > - * 'used_targets' will become unavailable in future > - * passes. This limits some opportunities for > - * multiple source nodes to share a destination. > - */ > - nodes_or(used_targets, used_targets, this_pass); > - > - for_each_node_mask(node, this_pass) { > - best_distance = -1; > - > - /* > - * Try to set up the migration path for the node, and the target > - * migration nodes can be multiple, so doing a loop to find all > - * the target nodes if they all have a best node distance. > - */ > - do { > - int target_node = > - establish_migrate_target(node, &used_targets, > - best_distance); > - > - if (target_node == NUMA_NO_NODE) > - break; > - > - if (best_distance == -1) > - best_distance = node_distance(node, target_node); > - > - /* > - * Visit targets from this pass in the next pass. > - * Eventually, every node will have been part of > - * a pass, and will become set in 'used_targets'. > - */ > - node_set(target_node, next_pass); > - } while (1); > - } > - /* > - * 'next_pass' contains nodes which became migration > - * targets in this pass. Make additional passes until > - * no more migrations targets are available. > - */ > - if (!nodes_empty(next_pass)) > - goto again; > -} > - > -/* > - * For callers that do not hold get_online_mems() already. > - */ > -void set_migration_target_nodes(void) > -{ > - get_online_mems(); > - __set_migration_target_nodes(); > - put_online_mems(); > -} > - > -/* > - * This leaves migrate-on-reclaim transiently disabled between > - * the MEM_GOING_OFFLINE and MEM_OFFLINE events. 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. > - * > - * These callbacks already hold get_online_mems(). That is why > - * __set_migration_target_nodes() can be used as opposed to > - * set_migration_target_nodes(). > - */ > -#ifdef CONFIG_MEMORY_HOTPLUG > -static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, > - unsigned long action, void *_arg) > -{ > - struct memory_notify *arg = _arg; > - > - /* > - * Only update the node migration order when a node is > - * changing status, like online->offline. This avoids > - * the overhead of synchronize_rcu() in most cases. > - */ > - if (arg->status_change_nid < 0) > - return notifier_from_errno(0); > - > - switch (action) { > - case MEM_GOING_OFFLINE: > - /* > - * Make sure there are not transient states where > - * an offline node is a migration target. This > - * will leave migration disabled until the offline > - * completes and the MEM_OFFLINE case below runs. > - */ > - disable_all_migrate_targets(); > - break; > - case MEM_OFFLINE: > - case MEM_ONLINE: > - /* > - * Recalculate the target nodes once the node > - * reaches its final state (online or offline). > - */ > - __set_migration_target_nodes(); > - break; > - case MEM_CANCEL_OFFLINE: > - /* > - * MEM_GOING_OFFLINE disabled all the migration > - * targets. Reenable them. > - */ > - __set_migration_target_nodes(); > - break; > - case MEM_GOING_ONLINE: > - case MEM_CANCEL_ONLINE: > - break; > - } > - > - return notifier_from_errno(0); > -} > -#endif > - > -void __init migrate_on_reclaim_init(void) > -{ > - node_demotion = kcalloc(nr_node_ids, > - sizeof(struct demotion_nodes), > - GFP_KERNEL); > - WARN_ON(!node_demotion); > -#ifdef CONFIG_MEMORY_HOTPLUG > - hotplug_memory_notifier(migrate_on_reclaim_callback, 100); > -#endif > - /* > - * At this point, all numa nodes with memory/CPus have their state > - * properly set, so we can build the demotion order now. > - * Let us hold the cpu_hotplug lock just, as we could possibily have > - * CPU hotplug events during boot. > - */ > - cpus_read_lock(); > - set_migration_target_nodes(); > - cpus_read_unlock(); > -} > #endif /* CONFIG_NUMA */ > - > - > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 373d2730fcf2..35c6ff97cf29 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -28,7 +28,6 @@ > #include <linux/mm_inline.h> > #include <linux/page_ext.h> > #include <linux/page_owner.h> > -#include <linux/migrate.h> > > #include "internal.h" > > @@ -2060,7 +2059,6 @@ static int vmstat_cpu_online(unsigned int cpu) > > if (!node_state(cpu_to_node(cpu), N_CPU)) { > node_set_state(cpu_to_node(cpu), N_CPU); > - set_migration_target_nodes(); > } > > return 0; > @@ -2085,7 +2083,6 @@ static int vmstat_cpu_dead(unsigned int cpu) > return 0; > > node_clear_state(node, N_CPU); > - set_migration_target_nodes(); > > return 0; > } > @@ -2118,7 +2115,6 @@ void __init init_mm_internals(void) > > start_shepherd_timer(); > #endif > - migrate_on_reclaim_init(); > #ifdef CONFIG_PROC_FS > proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op); > proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
"Huang, Ying" <ying.huang@intel.com> writes: > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > + */ .... >> +int next_demotion_node(int node) >> +{ >> + struct demotion_nodes *nd; >> + int target; >> + >> + if (!node_demotion) >> + return NUMA_NO_NODE; >> + >> + nd = &node_demotion[node]; >> + >> + /* >> + * node_demotion[] is updated without excluding this >> + * function from running. >> + * >> + * Make sure to use RCU over entire code blocks if >> + * node_demotion[] reads need to be consistent. >> + */ >> + rcu_read_lock(); >> + /* >> + * If there are multiple target nodes, just select one >> + * target node randomly. >> + * >> + * In addition, we can also use round-robin to select >> + * target node, but we should introduce another variable >> + * for node_demotion[] to record last selected target node, >> + * that may cause cache ping-pong due to the changing of >> + * last target node. Or introducing per-cpu data to avoid >> + * caching issue, which seems more complicated. So selecting >> + * target node randomly seems better until now. >> + */ >> + target = node_random(&nd->preferred); > > Don't find code to optimize node_random() for weight == 1 case, forget > to do that? I guess you suggested to do that as the patch for node_random or did I got the review feedback wrong? https://lore.kernel.org/linux-mm/87y1wdn30p.fsf@yhuang6-desk2.ccr.corp.intel.com The change for node_random will be patch outside this series. -aneesh
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > "Huang, Ying" <ying.huang@intel.com> writes: > >> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: >> + */ > > .... > >>> +int next_demotion_node(int node) >>> +{ >>> + struct demotion_nodes *nd; >>> + int target; >>> + >>> + if (!node_demotion) >>> + return NUMA_NO_NODE; >>> + >>> + nd = &node_demotion[node]; >>> + >>> + /* >>> + * node_demotion[] is updated without excluding this >>> + * function from running. >>> + * >>> + * Make sure to use RCU over entire code blocks if >>> + * node_demotion[] reads need to be consistent. >>> + */ >>> + rcu_read_lock(); >>> + /* >>> + * If there are multiple target nodes, just select one >>> + * target node randomly. >>> + * >>> + * In addition, we can also use round-robin to select >>> + * target node, but we should introduce another variable >>> + * for node_demotion[] to record last selected target node, >>> + * that may cause cache ping-pong due to the changing of >>> + * last target node. Or introducing per-cpu data to avoid >>> + * caching issue, which seems more complicated. So selecting >>> + * target node randomly seems better until now. >>> + */ >>> + target = node_random(&nd->preferred); >> >> Don't find code to optimize node_random() for weight == 1 case, forget >> to do that? > > I guess you suggested to do that as the patch for node_random or did I > got the review feedback wrong? Yes. > https://lore.kernel.org/linux-mm/87y1wdn30p.fsf@yhuang6-desk2.ccr.corp.intel.com > > The change for node_random will be patch outside this series. I think we can include it in this series. Because the series provide more information about why we need the change. Best Regards, Huang, Ying
diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h index 4f4baf0bf430..e56a57c6ef78 100644 --- a/include/linux/memory-tiers.h +++ b/include/linux/memory-tiers.h @@ -31,6 +31,14 @@ struct memory_dev_type { #ifdef CONFIG_NUMA extern bool numa_demotion_enabled; struct memory_dev_type *init_node_memory_type(int node, struct memory_dev_type *default_type); +#ifdef CONFIG_MIGRATION +int next_demotion_node(int node); +#else +static inline int next_demotion_node(int node) +{ + return NUMA_NO_NODE; +} +#endif #else @@ -39,5 +47,10 @@ static inline struct memory_dev_type *init_node_memory_type(int node, struct mem { return ERR_PTR(-EINVAL); } + +static inline int next_demotion_node(int node) +{ + return NUMA_NO_NODE; +} #endif /* CONFIG_NUMA */ #endif /* _LINUX_MEMORY_TIERS_H */ diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 43e737215f33..93fab62e6548 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -75,19 +75,6 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, #endif /* CONFIG_MIGRATION */ -#if defined(CONFIG_MIGRATION) && defined(CONFIG_NUMA) -extern void set_migration_target_nodes(void); -extern void migrate_on_reclaim_init(void); -extern int next_demotion_node(int node); -#else -static inline void set_migration_target_nodes(void) {} -static inline void migrate_on_reclaim_init(void) {} -static inline int next_demotion_node(int node) -{ - return NUMA_NO_NODE; -} -#endif - #ifdef CONFIG_COMPACTION extern int PageMovable(struct page *page); extern void __SetPageMovable(struct page *page, struct address_space *mapping); diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 109be75fa554..60845aa74afc 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -2,8 +2,11 @@ #include <linux/slab.h> #include <linux/lockdep.h> #include <linux/memory.h> +#include <linux/random.h> #include <linux/memory-tiers.h> +#include "internal.h" + struct memory_tier { /* hierarchy of memory tiers */ struct list_head list; @@ -17,9 +20,74 @@ struct memory_tier { int adistance_start; }; +struct demotion_nodes { + nodemask_t preferred; +}; + static DEFINE_MUTEX(memory_tier_lock); static LIST_HEAD(memory_tiers); struct memory_dev_type *node_memory_types[MAX_NUMNODES]; +#ifdef CONFIG_MIGRATION +/* + * node_demotion[] examples: + * + * Example 1: + * + * Node 0 & 1 are CPU + DRAM nodes, node 2 & 3 are PMEM nodes. + * + * node distances: + * node 0 1 2 3 + * 0 10 20 30 40 + * 1 20 10 40 30 + * 2 30 40 10 40 + * 3 40 30 40 10 + * + * memory_tiers0 = 0-1 + * memory_tiers1 = 2-3 + * + * node_demotion[0].preferred = 2 + * node_demotion[1].preferred = 3 + * node_demotion[2].preferred = <empty> + * node_demotion[3].preferred = <empty> + * + * Example 2: + * + * Node 0 & 1 are CPU + DRAM nodes, node 2 is memory-only DRAM node. + * + * node distances: + * node 0 1 2 + * 0 10 20 30 + * 1 20 10 30 + * 2 30 30 10 + * + * memory_tiers0 = 0-2 + * + * node_demotion[0].preferred = <empty> + * node_demotion[1].preferred = <empty> + * node_demotion[2].preferred = <empty> + * + * Example 3: + * + * Node 0 is CPU + DRAM nodes, Node 1 is HBM node, node 2 is PMEM node. + * + * node distances: + * node 0 1 2 + * 0 10 20 30 + * 1 20 10 40 + * 2 30 40 10 + * + * memory_tiers0 = 1 + * memory_tiers1 = 0 + * memory_tiers2 = 2 + * + * node_demotion[0].preferred = 2 + * node_demotion[1].preferred = 0 + * node_demotion[2].preferred = <empty> + * + */ +static struct demotion_nodes *node_demotion __read_mostly; +#endif /* CONFIG_MIGRATION */ + /* * For now let's have 4 memory tier below default DRAM tier. */ @@ -82,6 +150,144 @@ static struct memory_tier *__node_get_memory_tier(int node) return NULL; } +#ifdef CONFIG_MIGRATION +/** + * next_demotion_node() - Get the next node in the demotion path + * @node: The starting node to lookup the next node + * + * Return: node id for next memory node in the demotion path hierarchy + * from @node; NUMA_NO_NODE if @node is terminal. This does not keep + * @node online or guarantee that it *continues* to be the next demotion + * target. + */ +int next_demotion_node(int node) +{ + struct demotion_nodes *nd; + int target; + + if (!node_demotion) + return NUMA_NO_NODE; + + nd = &node_demotion[node]; + + /* + * node_demotion[] is updated without excluding this + * function from running. + * + * Make sure to use RCU over entire code blocks if + * node_demotion[] reads need to be consistent. + */ + rcu_read_lock(); + /* + * If there are multiple target nodes, just select one + * target node randomly. + * + * In addition, we can also use round-robin to select + * target node, but we should introduce another variable + * for node_demotion[] to record last selected target node, + * that may cause cache ping-pong due to the changing of + * last target node. Or introducing per-cpu data to avoid + * caching issue, which seems more complicated. So selecting + * target node randomly seems better until now. + */ + target = node_random(&nd->preferred); + rcu_read_unlock(); + + return target; +} + +static void disable_all_demotion_targets(void) +{ + int node; + + for_each_node_state(node, N_MEMORY) + node_demotion[node].preferred = NODE_MASK_NONE; + /* + * Ensure that the "disable" is visible across the system. + * Readers will see either a combination of before+disable + * state or disable+after. They will never see before and + * after state together. + */ + synchronize_rcu(); +} + +static __always_inline nodemask_t get_memtier_nodemask(struct memory_tier *memtier) +{ + nodemask_t nodes = NODE_MASK_NONE; + struct memory_dev_type *memtype; + + list_for_each_entry(memtype, &memtier->memory_types, tier_sibiling) + nodes_or(nodes, nodes, memtype->nodes); + + return nodes; +} + +/* + * Find an automatic demotion target for all memory + * nodes. Failing here is OK. It might just indicate + * being at the end of a chain. + */ +static void establish_demotion_targets(void) +{ + struct memory_tier *memtier; + struct demotion_nodes *nd; + int target = NUMA_NO_NODE, node; + int distance, best_distance; + nodemask_t tier_nodes; + + lockdep_assert_held_once(&memory_tier_lock); + + if (!node_demotion || !IS_ENABLED(CONFIG_MIGRATION)) + return; + + disable_all_demotion_targets(); + + for_each_node_state(node, N_MEMORY) { + best_distance = -1; + nd = &node_demotion[node]; + + memtier = __node_get_memory_tier(node); + if (!memtier || list_is_first(&memtier->list, &memory_tiers)) + continue; + /* + * Get the lower memtier to find the demotion node list. + */ + memtier = list_prev_entry(memtier, list); + tier_nodes = get_memtier_nodemask(memtier); + /* + * find_next_best_node, use 'used' nodemask as a skip list. + * Add all memory nodes except the selected memory tier + * nodelist to skip list so that we find the best node from the + * memtier nodelist. + */ + nodes_andnot(tier_nodes, node_states[N_MEMORY], tier_nodes); + + /* + * Find all the nodes in the memory tier node list of same best distance. + * add them to the preferred mask. We randomly select between nodes + * in the preferred mask when allocating pages during demotion. + */ + do { + target = find_next_best_node(node, &tier_nodes); + if (target == NUMA_NO_NODE) + break; + + distance = node_distance(node, target); + if (distance == best_distance || best_distance == -1) { + best_distance = distance; + node_set(target, nd->preferred); + } else { + break; + } + } while (1); + } +} + +#else +static inline void disable_all_demotion_targets(void) {} +static inline void establish_demotion_targets(void) {} +#endif /* CONFIG_MIGRATION */ + static void init_node_memory_tier(int node) { struct memory_tier *memtier; @@ -89,6 +295,13 @@ static void init_node_memory_tier(int node) mutex_lock(&memory_tier_lock); memtier = __node_get_memory_tier(node); + /* + * if node is already part of the tier proceed with the + * current tier value, because we might want to establish + * new migration paths now. The node might be added to a tier + * before it was made part of N_MEMORY, hence estabilish_demotion_targets + * will have skipped this node. + */ if (!memtier) { struct memory_dev_type *memtype; @@ -99,6 +312,7 @@ static void init_node_memory_tier(int node) memtype = node_memory_types[node]; memtier = find_create_memory_tier(memtype); } + establish_demotion_targets(); mutex_unlock(&memory_tier_lock); } @@ -125,6 +339,7 @@ static void clear_node_memory_tier(int node) if (list_empty(¤t_memtier->memory_types)) destroy_memory_tier(current_memtier); } + establish_demotion_targets(); } mutex_unlock(&memory_tier_lock); } @@ -182,7 +397,11 @@ static int __init memory_tier_init(void) panic("%s() failed to register memory tier: %ld\n", __func__, PTR_ERR(memtier)); mutex_unlock(&memory_tier_lock); - +#ifdef CONFIG_MIGRATION + node_demotion = kcalloc(MAX_NUMNODES, sizeof(struct demotion_nodes), + GFP_KERNEL); + WARN_ON(!node_demotion); +#endif hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRIO); return 0; } diff --git a/mm/migrate.c b/mm/migrate.c index fce7d4a9e940..c758c9c21d7d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2117,398 +2117,4 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, return 0; } #endif /* CONFIG_NUMA_BALANCING */ - -/* - * node_demotion[] example: - * - * Consider a system with two sockets. Each socket has - * three classes of memory attached: fast, medium and slow. - * Each memory class is placed in its own NUMA node. The - * CPUs are placed in the node with the "fast" memory. The - * 6 NUMA nodes (0-5) might be split among the sockets like - * this: - * - * Socket A: 0, 1, 2 - * Socket B: 3, 4, 5 - * - * When Node 0 fills up, its memory should be migrated to - * Node 1. When Node 1 fills up, it should be migrated to - * Node 2. The migration path start on the nodes with the - * processors (since allocations default to this node) and - * fast memory, progress through medium and end with the - * slow memory: - * - * 0 -> 1 -> 2 -> stop - * 3 -> 4 -> 5 -> stop - * - * This is represented in the node_demotion[] like this: - * - * { nr=1, nodes[0]=1 }, // Node 0 migrates to 1 - * { nr=1, nodes[0]=2 }, // Node 1 migrates to 2 - * { nr=0, nodes[0]=-1 }, // Node 2 does not migrate - * { nr=1, nodes[0]=4 }, // Node 3 migrates to 4 - * { nr=1, nodes[0]=5 }, // Node 4 migrates to 5 - * { nr=0, nodes[0]=-1 }, // Node 5 does not migrate - * - * Moreover some systems may have multiple slow memory nodes. - * Suppose a system has one socket with 3 memory nodes, node 0 - * is fast memory type, and node 1/2 both are slow memory - * type, and the distance between fast memory node and slow - * memory node is same. So the migration path should be: - * - * 0 -> 1/2 -> stop - * - * This is represented in the node_demotion[] like this: - * { nr=2, {nodes[0]=1, nodes[1]=2} }, // Node 0 migrates to node 1 and node 2 - * { nr=0, nodes[0]=-1, }, // Node 1 dose not migrate - * { nr=0, nodes[0]=-1, }, // Node 2 does not migrate - */ - -/* - * Writes to this array occur without locking. Cycles are - * not allowed: Node X demotes to Y which demotes to X... - * - * If multiple reads are performed, a single rcu_read_lock() - * must be held over all reads to ensure that no cycles are - * observed. - */ -#define DEFAULT_DEMOTION_TARGET_NODES 15 - -#if MAX_NUMNODES < DEFAULT_DEMOTION_TARGET_NODES -#define DEMOTION_TARGET_NODES (MAX_NUMNODES - 1) -#else -#define DEMOTION_TARGET_NODES DEFAULT_DEMOTION_TARGET_NODES -#endif - -struct demotion_nodes { - unsigned short nr; - short nodes[DEMOTION_TARGET_NODES]; -}; - -static struct demotion_nodes *node_demotion __read_mostly; - -/** - * next_demotion_node() - Get the next node in the demotion path - * @node: The starting node to lookup the next node - * - * Return: node id for next memory node in the demotion path hierarchy - * from @node; NUMA_NO_NODE if @node is terminal. This does not keep - * @node online or guarantee that it *continues* to be the next demotion - * target. - */ -int next_demotion_node(int node) -{ - struct demotion_nodes *nd; - unsigned short target_nr, index; - int target; - - if (!node_demotion) - return NUMA_NO_NODE; - - nd = &node_demotion[node]; - - /* - * node_demotion[] is updated without excluding this - * function from running. RCU doesn't provide any - * compiler barriers, so the READ_ONCE() is required - * to avoid compiler reordering or read merging. - * - * Make sure to use RCU over entire code blocks if - * node_demotion[] reads need to be consistent. - */ - rcu_read_lock(); - target_nr = READ_ONCE(nd->nr); - - switch (target_nr) { - case 0: - target = NUMA_NO_NODE; - goto out; - case 1: - index = 0; - break; - default: - /* - * If there are multiple target nodes, just select one - * target node randomly. - * - * In addition, we can also use round-robin to select - * target node, but we should introduce another variable - * for node_demotion[] to record last selected target node, - * that may cause cache ping-pong due to the changing of - * last target node. Or introducing per-cpu data to avoid - * caching issue, which seems more complicated. So selecting - * target node randomly seems better until now. - */ - index = get_random_int() % target_nr; - break; - } - - target = READ_ONCE(nd->nodes[index]); - -out: - rcu_read_unlock(); - return target; -} - -/* Disable reclaim-based migration. */ -static void __disable_all_migrate_targets(void) -{ - int node, i; - - if (!node_demotion) - return; - - for_each_online_node(node) { - node_demotion[node].nr = 0; - for (i = 0; i < DEMOTION_TARGET_NODES; i++) - node_demotion[node].nodes[i] = NUMA_NO_NODE; - } -} - -static void disable_all_migrate_targets(void) -{ - __disable_all_migrate_targets(); - - /* - * Ensure that the "disable" is visible across the system. - * Readers will see either a combination of before+disable - * state or disable+after. They will never see before and - * after state together. - * - * The before+after state together might have cycles and - * could cause readers to do things like loop until this - * function finishes. This ensures they can only see a - * single "bad" read and would, for instance, only loop - * once. - */ - synchronize_rcu(); -} - -/* - * Find an automatic demotion target for 'node'. - * Failing here is OK. It might just indicate - * being at the end of a chain. - */ -static int establish_migrate_target(int node, nodemask_t *used, - int best_distance) -{ - int migration_target, index, val; - struct demotion_nodes *nd; - - if (!node_demotion) - return NUMA_NO_NODE; - - nd = &node_demotion[node]; - - migration_target = find_next_best_node(node, used); - if (migration_target == NUMA_NO_NODE) - return NUMA_NO_NODE; - - /* - * If the node has been set a migration target node before, - * which means it's the best distance between them. Still - * check if this node can be demoted to other target nodes - * if they have a same best distance. - */ - if (best_distance != -1) { - val = node_distance(node, migration_target); - if (val > best_distance) - goto out_clear; - } - - index = nd->nr; - if (WARN_ONCE(index >= DEMOTION_TARGET_NODES, - "Exceeds maximum demotion target nodes\n")) - goto out_clear; - - nd->nodes[index] = migration_target; - nd->nr++; - - return migration_target; -out_clear: - node_clear(migration_target, *used); - return NUMA_NO_NODE; -} - -/* - * When memory fills up on a node, memory contents can be - * automatically migrated to another node instead of - * discarded at reclaim. - * - * Establish a "migration path" which will start at nodes - * with CPUs and will follow the priorities used to build the - * page allocator zonelists. - * - * The difference here is that cycles must be avoided. If - * node0 migrates to node1, then neither node1, nor anything - * node1 migrates to can migrate to node0. Also one node can - * be migrated to multiple nodes if the target nodes all have - * a same best-distance against the source node. - * - * This function can run simultaneously with readers of - * node_demotion[]. However, it can not run simultaneously - * with itself. Exclusion is provided by memory hotplug events - * being single-threaded. - */ -static void __set_migration_target_nodes(void) -{ - nodemask_t next_pass; - nodemask_t this_pass; - nodemask_t used_targets = NODE_MASK_NONE; - int node, best_distance; - - /* - * Avoid any oddities like cycles that could occur - * from changes in the topology. This will leave - * a momentary gap when migration is disabled. - */ - disable_all_migrate_targets(); - - /* - * Allocations go close to CPUs, first. Assume that - * the migration path starts at the nodes with CPUs. - */ - next_pass = node_states[N_CPU]; -again: - this_pass = next_pass; - next_pass = NODE_MASK_NONE; - /* - * To avoid cycles in the migration "graph", ensure - * that migration sources are not future targets by - * setting them in 'used_targets'. Do this only - * once per pass so that multiple source nodes can - * share a target node. - * - * 'used_targets' will become unavailable in future - * passes. This limits some opportunities for - * multiple source nodes to share a destination. - */ - nodes_or(used_targets, used_targets, this_pass); - - for_each_node_mask(node, this_pass) { - best_distance = -1; - - /* - * Try to set up the migration path for the node, and the target - * migration nodes can be multiple, so doing a loop to find all - * the target nodes if they all have a best node distance. - */ - do { - int target_node = - establish_migrate_target(node, &used_targets, - best_distance); - - if (target_node == NUMA_NO_NODE) - break; - - if (best_distance == -1) - best_distance = node_distance(node, target_node); - - /* - * Visit targets from this pass in the next pass. - * Eventually, every node will have been part of - * a pass, and will become set in 'used_targets'. - */ - node_set(target_node, next_pass); - } while (1); - } - /* - * 'next_pass' contains nodes which became migration - * targets in this pass. Make additional passes until - * no more migrations targets are available. - */ - if (!nodes_empty(next_pass)) - goto again; -} - -/* - * For callers that do not hold get_online_mems() already. - */ -void set_migration_target_nodes(void) -{ - get_online_mems(); - __set_migration_target_nodes(); - put_online_mems(); -} - -/* - * This leaves migrate-on-reclaim transiently disabled between - * the MEM_GOING_OFFLINE and MEM_OFFLINE events. 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. - * - * These callbacks already hold get_online_mems(). That is why - * __set_migration_target_nodes() can be used as opposed to - * set_migration_target_nodes(). - */ -#ifdef CONFIG_MEMORY_HOTPLUG -static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, - unsigned long action, void *_arg) -{ - struct memory_notify *arg = _arg; - - /* - * Only update the node migration order when a node is - * changing status, like online->offline. This avoids - * the overhead of synchronize_rcu() in most cases. - */ - if (arg->status_change_nid < 0) - return notifier_from_errno(0); - - switch (action) { - case MEM_GOING_OFFLINE: - /* - * Make sure there are not transient states where - * an offline node is a migration target. This - * will leave migration disabled until the offline - * completes and the MEM_OFFLINE case below runs. - */ - disable_all_migrate_targets(); - break; - case MEM_OFFLINE: - case MEM_ONLINE: - /* - * Recalculate the target nodes once the node - * reaches its final state (online or offline). - */ - __set_migration_target_nodes(); - break; - case MEM_CANCEL_OFFLINE: - /* - * MEM_GOING_OFFLINE disabled all the migration - * targets. Reenable them. - */ - __set_migration_target_nodes(); - break; - case MEM_GOING_ONLINE: - case MEM_CANCEL_ONLINE: - break; - } - - return notifier_from_errno(0); -} -#endif - -void __init migrate_on_reclaim_init(void) -{ - node_demotion = kcalloc(nr_node_ids, - sizeof(struct demotion_nodes), - GFP_KERNEL); - WARN_ON(!node_demotion); -#ifdef CONFIG_MEMORY_HOTPLUG - hotplug_memory_notifier(migrate_on_reclaim_callback, 100); -#endif - /* - * At this point, all numa nodes with memory/CPus have their state - * properly set, so we can build the demotion order now. - * Let us hold the cpu_hotplug lock just, as we could possibily have - * CPU hotplug events during boot. - */ - cpus_read_lock(); - set_migration_target_nodes(); - cpus_read_unlock(); -} #endif /* CONFIG_NUMA */ - - diff --git a/mm/vmstat.c b/mm/vmstat.c index 373d2730fcf2..35c6ff97cf29 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -28,7 +28,6 @@ #include <linux/mm_inline.h> #include <linux/page_ext.h> #include <linux/page_owner.h> -#include <linux/migrate.h> #include "internal.h" @@ -2060,7 +2059,6 @@ static int vmstat_cpu_online(unsigned int cpu) if (!node_state(cpu_to_node(cpu), N_CPU)) { node_set_state(cpu_to_node(cpu), N_CPU); - set_migration_target_nodes(); } return 0; @@ -2085,7 +2083,6 @@ static int vmstat_cpu_dead(unsigned int cpu) return 0; node_clear_state(node, N_CPU); - set_migration_target_nodes(); return 0; } @@ -2118,7 +2115,6 @@ void __init init_mm_internals(void) start_shepherd_timer(); #endif - migrate_on_reclaim_init(); #ifdef CONFIG_PROC_FS proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op); proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
This patch switch the demotion target building logic to use memory tiers instead of NUMA distance. All N_MEMORY NUMA nodes will be placed in the default memory tier and additional memory tiers will be added by drivers like dax kmem. This patch builds the demotion target for a NUMA node by looking at all memory tiers below the tier to which the NUMA node belongs. The closest node in the immediately following memory tier is used as a demotion target. Since we are now only building demotion target for N_MEMORY NUMA nodes the CPU hotplug calls are removed in this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- include/linux/memory-tiers.h | 13 ++ include/linux/migrate.h | 13 -- mm/memory-tiers.c | 221 +++++++++++++++++++- mm/migrate.c | 394 ----------------------------------- mm/vmstat.c | 4 - 5 files changed, 233 insertions(+), 412 deletions(-)