kernel/rcu/sync.c

File Facts

System

Linux kernel

Corpus path

kernel/rcu/sync.c

Extension

.c

Size

5914 bytes

Lines

191

Domain

Core OS

Bucket

Scheduler, Processes, Timers, Sync, And Syscalls

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

• linux/rcu_sync.h
• linux/sched.h

Detected Declarations

• function rcu_sync_init
• function rcu_sync_call
• function rcu_sync_func
• function rcu_sync_enter
• function rcu_sync_exit
• function rcu_sync_dtor

Annotated Snippet

if (rsp->gp_state == GP_PASSED) {
			WRITE_ONCE(rsp->gp_state, GP_EXIT);
			rcu_sync_call(rsp);
		} else if (rsp->gp_state == GP_EXIT) {
			WRITE_ONCE(rsp->gp_state, GP_REPLAY);
		}
	}
	spin_unlock_irq(&rsp->rss_lock);
}

/**
 * rcu_sync_dtor() - Clean up an rcu_sync structure
 * @rsp: Pointer to rcu_sync structure to be cleaned up
 */
void rcu_sync_dtor(struct rcu_sync *rsp)
{
	int gp_state;

	WARN_ON_ONCE(READ_ONCE(rsp->gp_state) == GP_PASSED);

	spin_lock_irq(&rsp->rss_lock);
	WARN_ON_ONCE(rsp->gp_count);
	if (rsp->gp_state == GP_REPLAY)
		WRITE_ONCE(rsp->gp_state, GP_EXIT);
	gp_state = rsp->gp_state;
	spin_unlock_irq(&rsp->rss_lock);

	if (gp_state != GP_IDLE) {
		rcu_barrier();
		WARN_ON_ONCE(rsp->gp_state != GP_IDLE);
	}
}

Annotation

• Immediate include surface: `linux/rcu_sync.h`, `linux/sched.h`.
• Detected declarations: `function rcu_sync_init`, `function rcu_sync_call`, `function rcu_sync_func`, `function rcu_sync_enter`, `function rcu_sync_exit`, `function rcu_sync_dtor`.
• Atlas domain: Core OS / Scheduler, Processes, Timers, Sync, And Syscalls.
• 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.