diff options
| -rw-r--r-- | include/linux/memory-tiers.h | 18 | ||||
| -rw-r--r-- | mm/Makefile | 1 | ||||
| -rw-r--r-- | mm/memory-tiers.c | 129 |
3 files changed, 148 insertions, 0 deletions
diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h new file mode 100644 index 000000000000..ecada7bf4091 --- /dev/null +++ b/include/linux/memory-tiers.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_MEMORY_TIERS_H +#define _LINUX_MEMORY_TIERS_H + +/* + * Each tier cover a abstrace distance chunk size of 128 + */ +#define MEMTIER_CHUNK_BITS 7 +#define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS) +/* + * Smaller abstract distance values imply faster (higher) memory tiers. Offset + * the DRAM adistance so that we can accommodate devices with a slightly lower + * adistance value (slightly faster) than default DRAM adistance to be part of + * the same memory tier. + */ +#define MEMTIER_ADISTANCE_DRAM ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1)) + +#endif /* _LINUX_MEMORY_TIERS_H */ diff --git a/mm/Makefile b/mm/Makefile index 9a564f836403..488f604e77e0 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -92,6 +92,7 @@ obj-$(CONFIG_KFENCE) += kfence/ obj-$(CONFIG_FAILSLAB) += failslab.o obj-$(CONFIG_MEMTEST) += memtest.o obj-$(CONFIG_MIGRATION) += migrate.o +obj-$(CONFIG_NUMA) += memory-tiers.o obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o obj-$(CONFIG_PAGE_COUNTER) += page_counter.o diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c new file mode 100644 index 000000000000..1f494e69776a --- /dev/null +++ b/mm/memory-tiers.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/types.h> +#include <linux/nodemask.h> +#include <linux/slab.h> +#include <linux/lockdep.h> +#include <linux/memory-tiers.h> + +struct memory_tier { + /* hierarchy of memory tiers */ + struct list_head list; + /* list of all memory types part of this tier */ + struct list_head memory_types; + /* + * start value of abstract distance. memory tier maps + * an abstract distance range, + * adistance_start .. adistance_start + MEMTIER_CHUNK_SIZE + */ + int adistance_start; +}; + +struct memory_dev_type { + /* list of memory types that are part of same tier as this type */ + struct list_head tier_sibiling; + /* abstract distance for this specific memory type */ + int adistance; + /* Nodes of same abstract distance */ + nodemask_t nodes; + struct memory_tier *memtier; +}; + +static DEFINE_MUTEX(memory_tier_lock); +static LIST_HEAD(memory_tiers); +static struct memory_dev_type *node_memory_types[MAX_NUMNODES]; +/* + * For now we can have 4 faster memory tiers with smaller adistance + * than default DRAM tier. + */ +static struct memory_dev_type default_dram_type = { + .adistance = MEMTIER_ADISTANCE_DRAM, + .tier_sibiling = LIST_HEAD_INIT(default_dram_type.tier_sibiling), +}; + +static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memtype) +{ + bool found_slot = false; + struct memory_tier *memtier, *new_memtier; + int adistance = memtype->adistance; + unsigned int memtier_adistance_chunk_size = MEMTIER_CHUNK_SIZE; + + lockdep_assert_held_once(&memory_tier_lock); + + /* + * If the memtype is already part of a memory tier, + * just return that. + */ + if (memtype->memtier) + return memtype->memtier; + + adistance = round_down(adistance, memtier_adistance_chunk_size); + list_for_each_entry(memtier, &memory_tiers, list) { + if (adistance == memtier->adistance_start) { + memtype->memtier = memtier; + list_add(&memtype->tier_sibiling, &memtier->memory_types); + return memtier; + } else if (adistance < memtier->adistance_start) { + found_slot = true; + break; + } + } + + new_memtier = kmalloc(sizeof(struct memory_tier), GFP_KERNEL); + if (!new_memtier) + return ERR_PTR(-ENOMEM); + + new_memtier->adistance_start = adistance; + INIT_LIST_HEAD(&new_memtier->list); + INIT_LIST_HEAD(&new_memtier->memory_types); + if (found_slot) + list_add_tail(&new_memtier->list, &memtier->list); + else + list_add_tail(&new_memtier->list, &memory_tiers); + memtype->memtier = new_memtier; + list_add(&memtype->tier_sibiling, &new_memtier->memory_types); + return new_memtier; +} + +static struct memory_tier *set_node_memory_tier(int node) +{ + struct memory_tier *memtier; + struct memory_dev_type *memtype; + + lockdep_assert_held_once(&memory_tier_lock); + + if (!node_state(node, N_MEMORY)) + return ERR_PTR(-EINVAL); + + if (!node_memory_types[node]) + node_memory_types[node] = &default_dram_type; + + memtype = node_memory_types[node]; + node_set(node, memtype->nodes); + memtier = find_create_memory_tier(memtype); + return memtier; +} + +static int __init memory_tier_init(void) +{ + int node; + struct memory_tier *memtier; + + mutex_lock(&memory_tier_lock); + /* + * Look at all the existing N_MEMORY nodes and add them to + * default memory tier or to a tier if we already have memory + * types assigned. + */ + for_each_node_state(node, N_MEMORY) { + memtier = set_node_memory_tier(node); + if (IS_ERR(memtier)) + /* + * Continue with memtiers we are able to setup + */ + break; + } + mutex_unlock(&memory_tier_lock); + + return 0; +} +subsys_initcall(memory_tier_init); |