tools/perf/util/db-export.c

File Facts

System

Linux kernel

Corpus path

tools/perf/util/db-export.c

Extension

.c

Size

15119 bytes

Lines

619

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• errno.h
• stdlib.h
• dso.h
• evsel.h
• machine.h
• thread.h
• comm.h
• symbol.h
• map.h
• event.h
• thread-stack.h
• callchain.h
• call-path.h
• db-export.h

Detected Declarations

• function Copyright
• function db_export__exit
• function db_export__evsel
• function db_export__machine
• function db_export__thread
• function __db_export__comm
• function db_export__comm
• function db_export__exec_comm
• function db_export__comm_thread
• function db_export__dso
• function db_export__symbol
• function db_ids_from_al
• function db_export__branch_type
• function db_export__threads
• function db_export__sample
• function db_export__branch_types
• function db_export__call_path
• function db_export__call_return
• function db_export__pid_tid
• function db_export__switch

Annotated Snippet

pid_t pid = event->context_switch.next_prev_pid;
		pid_t tid = event->context_switch.next_prev_tid;

		err = db_export__pid_tid(dbe, machine, pid, tid, &th_b_id,
					 &comm_b, &is_idle_b);
		if (err)
			return err;
	}

	/*
	 * Do not export if both threads are unknown (i.e. not being traced),
	 * or one is unknown and the other is the idle task.
	 */
	if ((!th_a_id || is_idle_a) && (!th_b_id || is_idle_b))
		return 0;

	db_id = ++dbe->context_switch_last_db_id;

	if (out) {
		th_out_id   = th_a_id;
		th_in_id    = th_b_id;
		comm_out_id = comm_a ? comm_a->db_id : 0;
		comm_in_id  = comm_b ? comm_b->db_id : 0;
	} else {
		th_out_id   = th_b_id;
		th_in_id    = th_a_id;
		comm_out_id = comm_b ? comm_b->db_id : 0;
		comm_in_id  = comm_a ? comm_a->db_id : 0;
	}

	if (dbe->export_context_switch)
		return dbe->export_context_switch(dbe, db_id, machine, sample,
						  th_out_id, comm_out_id,
						  th_in_id, comm_in_id, flags);
	return 0;
}

Annotation

• Immediate include surface: `errno.h`, `stdlib.h`, `dso.h`, `evsel.h`, `machine.h`, `thread.h`, `comm.h`, `symbol.h`.
• Detected declarations: `function Copyright`, `function db_export__exit`, `function db_export__evsel`, `function db_export__machine`, `function db_export__thread`, `function __db_export__comm`, `function db_export__comm`, `function db_export__exec_comm`, `function db_export__comm_thread`, `function db_export__dso`.
• Atlas domain: Support Tooling And Documentation / tools.
• 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.