https://github.com/torvalds/linux
Tip revision: ceaa837f96adb69c0df0397937cd74991d5d821a authored by Linus Torvalds on 12 February 2023, 22:10:17 UTC
Linux 6.2-rc8
Linux 6.2-rc8
Tip revision: ceaa837
memory-tiers.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MEMORY_TIERS_H
#define _LINUX_MEMORY_TIERS_H
#include <linux/types.h>
#include <linux/nodemask.h>
#include <linux/kref.h>
#include <linux/mmzone.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))
struct memory_tier;
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 kref kref;
};
#ifdef CONFIG_NUMA
extern bool numa_demotion_enabled;
struct memory_dev_type *alloc_memory_type(int adistance);
void destroy_memory_type(struct memory_dev_type *memtype);
void init_node_memory_type(int node, struct memory_dev_type *default_type);
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)
{
return NUMA_NO_NODE;
}
static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
*targets = NODE_MASK_NONE;
}
static inline bool node_is_toptier(int node)
{
return true;
}
#endif
#else
#define numa_demotion_enabled false
/*
* CONFIG_NUMA implementation returns non NULL error.
*/
static inline struct memory_dev_type *alloc_memory_type(int adistance)
{
return NULL;
}
static inline void destroy_memory_type(struct memory_dev_type *memtype)
{
}
static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
{
}
static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
{
}
static inline int next_demotion_node(int node)
{
return NUMA_NO_NODE;
}
static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
*targets = NODE_MASK_NONE;
}
static inline bool node_is_toptier(int node)
{
return true;
}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_MEMORY_TIERS_H */