include/linux/memory-tiers.h
Source file repositories/reference/linux-study-clean/include/linux/memory-tiers.h
File Facts
- System
- Linux kernel
- Corpus path
include/linux/memory-tiers.h- Extension
.h- Size
- 4132 bytes
- Lines
- 156
- Domain
- Core OS
- Bucket
- Core Kernel Interface
- Inferred role
- Core OS: implementation source
- Status
- source implementation candidate
Why This File Exists
Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
- Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/types.hlinux/nodemask.hlinux/kref.hlinux/mmzone.hlinux/notifier.h
Detected Declarations
struct memory_tierstruct memory_dev_typestruct access_coordinatefunction next_demotion_nodefunction node_get_allowed_targetsfunction node_is_toptierfunction put_memory_typefunction node_get_allowed_targetsfunction node_is_toptierfunction register_mt_adistance_algorithmfunction unregister_mt_adistance_algorithmfunction mt_calc_adistancefunction mt_set_default_dram_perffunction mt_perf_to_adistancefunction mt_put_memory_types
Annotated Snippet
struct memory_dev_type {
/* list of memory types that are part of same tier as this type */
struct list_head tier_sibling;
/* list of memory types that are managed by one driver */
struct list_head list;
/* abstract distance for this specific memory type */
int adistance;
/* Nodes of same abstract distance */
nodemask_t nodes;
struct kref kref;
};
struct access_coordinate;
#ifdef CONFIG_NUMA
extern bool numa_demotion_enabled;
extern struct memory_dev_type *default_dram_type;
extern nodemask_t default_dram_nodes;
struct memory_dev_type *alloc_memory_type(int adistance);
void put_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);
int register_mt_adistance_algorithm(struct notifier_block *nb);
int unregister_mt_adistance_algorithm(struct notifier_block *nb);
int mt_calc_adistance(int node, int *adist);
int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
const char *source);
int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
struct memory_dev_type *mt_find_alloc_memory_type(int adist,
struct list_head *memory_types);
void mt_put_memory_types(struct list_head *memory_types);
#ifdef CONFIG_NUMA_MIGRATION
int next_demotion_node(int node, const nodemask_t *allowed_mask);
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, const nodemask_t *allowed_mask)
{
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
#define default_dram_type NULL
#define default_dram_nodes NODE_MASK_NONE
/*
* CONFIG_NUMA implementation returns non NULL error.
*/
static inline struct memory_dev_type *alloc_memory_type(int adistance)
{
return NULL;
}
static inline void put_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, const nodemask_t *allowed_mask)
{
return NUMA_NO_NODE;
}
static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
*targets = NODE_MASK_NONE;
}
Annotation
- Immediate include surface: `linux/types.h`, `linux/nodemask.h`, `linux/kref.h`, `linux/mmzone.h`, `linux/notifier.h`.
- Detected declarations: `struct memory_tier`, `struct memory_dev_type`, `struct access_coordinate`, `function next_demotion_node`, `function node_get_allowed_targets`, `function node_is_toptier`, `function put_memory_type`, `function node_get_allowed_targets`, `function node_is_toptier`, `function register_mt_adistance_algorithm`.
- Atlas domain: Core OS / Core Kernel Interface.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.