mm/zsmalloc.c

File Facts

System

Linux kernel

Corpus path

mm/zsmalloc.c

Extension

.c

Size

56866 bytes

Lines

2272

Domain

Core OS

Bucket

Memory Management

Inferred role

Core OS: exported/initcall integration point

Status

integration 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/kernel.h
• linux/sched.h
• linux/errno.h
• linux/highmem.h
• linux/string.h
• linux/slab.h
• linux/scatterlist.h
• linux/spinlock.h
• linux/sprintf.h
• linux/shrinker.h
• linux/types.h
• linux/debugfs.h
• linux/zsmalloc.h
• linux/fs.h
• linux/workqueue.h
• zpdesc.h

Detected Declarations

• struct zs_size_stat
• struct size_class
• struct link_free
• struct zs_pool
• struct zspage_lock
• struct zspage
• enum fullness_group
• enum class_stat_type
• function zpdesc_set_first
• function zpdesc_inc_zone_page_state
• function zpdesc_dec_zone_page_state
• function free_zpdesc
• function zspage_lock_init
• function writers
• function zspage_read_unlock
• function zspage_write_trylock
• function zspage_write_unlock
• function SetZsHugePage
• function ZsHugePage
• function kick_deferred_free
• function cache_free_handle
• function cache_free_zspage
• function record_obj
• function is_first_zpdesc
• function get_zspage_inuse
• function mod_zspage_inuse
• function get_first_obj_offset
• function set_first_obj_offset
• function get_freeobj
• function set_freeobj
• function get_size_class_index
• function class_stat_add
• function class_stat_sub
• function class_stat_read
• function zs_stat_init
• function zs_stat_exit
• function zs_stats_size_show
• function zs_pool_stat_create
• function zs_pool_stat_destroy
• function zs_stat_init
• function insert_zspage
• function remove_zspage
• function fix_fullness_group
• function obj_to_location
• function obj_to_zpdesc
• function location_to_obj
• function handle_to_obj
• function obj_allocated

Annotated Snippet

module_init(zs_init);
module_exit(zs_exit);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");
MODULE_DESCRIPTION("zsmalloc memory allocator");

Annotation

• Immediate include surface: `linux/module.h`, `linux/kernel.h`, `linux/sched.h`, `linux/errno.h`, `linux/highmem.h`, `linux/string.h`, `linux/slab.h`, `linux/scatterlist.h`.
• Detected declarations: `struct zs_size_stat`, `struct size_class`, `struct link_free`, `struct zs_pool`, `struct zspage_lock`, `struct zspage`, `enum fullness_group`, `enum class_stat_type`, `function zpdesc_set_first`, `function zpdesc_inc_zone_page_state`.
• Atlas domain: Core OS / Memory Management.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

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.