include/linux/osq_lock.h

File Facts

System

Linux kernel

Corpus path

include/linux/osq_lock.h

Extension

.h

Size

912 bytes

Lines

37

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.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• struct optimistic_spin_queue
• function osq_lock_init
• function osq_is_locked

Annotated Snippet

struct optimistic_spin_queue {
	/*
	 * Stores an encoded value of the CPU # of the tail node in the queue.
	 * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
	 */
	atomic_t tail;
};

#define OSQ_UNLOCKED_VAL (0)

/* Init macro and function. */
#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }

static inline void osq_lock_init(struct optimistic_spin_queue *lock)
{
	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
}

extern bool osq_lock(struct optimistic_spin_queue *lock);
extern void osq_unlock(struct optimistic_spin_queue *lock);

static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
{
	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
}

#endif

Annotation

• Detected declarations: `struct optimistic_spin_queue`, `function osq_lock_init`, `function osq_is_locked`.
• Atlas domain: Core OS / Core Kernel Interface.
• Implementation status: source 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.