tools/tracing/rtla/src/timerlat_aa.c

File Facts

System

Linux kernel

Corpus path

tools/tracing/rtla/src/timerlat_aa.c

Extension

.c

Size

30766 bytes

Lines

1076

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

• stdlib.h
• errno.h
• timerlat.h
• unistd.h

Detected Declarations

• struct timerlat_aa_data
• struct timerlat_aa_context
• enum timelat_state
• function timerlat_aa_irq_latency
• function timerlat_aa_thread_latency
• function timerlat_aa_handler
• function timerlat_aa_nmi_handler
• function timerlat_aa_irq_handler
• function timerlat_aa_softirq_handler
• function timerlat_aa_thread_handler
• function timerlat_aa_stack_handler
• function timerlat_aa_sched_switch_handler
• function timerlat_aa_kworker_start_handler
• function timerlat_thread_analysis
• function timerlat_auto_analysis_collect_trace
• function timerlat_auto_analysis
• function timerlat_aa_destroy_seqs
• function timerlat_aa_init_seqs
• function timerlat_aa_unregister_events
• function timerlat_aa_register_events
• function timerlat_aa_destroy
• function timerlat_aa_init

Annotated Snippet

struct timerlat_aa_data {
	/* Current CPU state */
	int			curr_state;

	/* timerlat IRQ latency */
	unsigned long long	tlat_irq_seqnum;
	unsigned long long	tlat_irq_latency;
	unsigned long long	tlat_irq_timstamp;

	/* timerlat Thread latency */
	unsigned long long	tlat_thread_seqnum;
	unsigned long long	tlat_thread_latency;
	unsigned long long	tlat_thread_timstamp;

	/*
	 * Information about the thread running when the IRQ
	 * arrived.
	 *
	 * This can be blocking or interference, depending on the
	 * priority of the thread. Assuming timerlat is the highest
	 * prio, it is blocking. If timerlat has a lower prio, it is
	 * interference.
	 * note: "unsigned long long" because they are fetch using tep_get_field_val();
	 */
	unsigned long long	run_thread_pid;
	char			run_thread_comm[MAX_COMM];
	unsigned long long	thread_blocking_duration;
	unsigned long long	max_exit_idle_latency;

	/* Information about the timerlat timer irq */
	unsigned long long	timer_irq_start_time;
	unsigned long long	timer_irq_start_delay;
	unsigned long long	timer_irq_duration;
	unsigned long long	timer_exit_from_idle;

	/*
	 * Information about the last IRQ before the timerlat irq
	 * arrived.
	 *
	 * If now - timestamp is <= latency, it might have influenced
	 * in the timerlat irq latency. Otherwise, ignore it.
	 */
	unsigned long long	prev_irq_duration;
	unsigned long long	prev_irq_timstamp;

	/*
	 * Interference sum.
	 */
	unsigned long long	thread_nmi_sum;
	unsigned long long	thread_irq_sum;
	unsigned long long	thread_softirq_sum;
	unsigned long long	thread_thread_sum;

	/*
	 * Interference task information.
	 */
	struct trace_seq	*prev_irqs_seq;
	struct trace_seq	*nmi_seq;
	struct trace_seq	*irqs_seq;
	struct trace_seq	*softirqs_seq;
	struct trace_seq	*threads_seq;
	struct trace_seq	*stack_seq;

	/*
	 * Current thread.
	 */
	char			current_comm[MAX_COMM];
	unsigned long long	current_pid;

	/*
	 * Is the system running a kworker?
	 */
	unsigned long long	kworker;
	unsigned long long	kworker_func;
};

/*
 * The analysis context and system wide view
 */
struct timerlat_aa_context {
	int dump_tasks;
	enum stack_format stack_format;

	/* per CPU data */
	struct timerlat_aa_data *taa_data;

	/*
	 * required to translate function names and register
	 * events.
	 */

Annotation

• Immediate include surface: `stdlib.h`, `errno.h`, `timerlat.h`, `unistd.h`.
• Detected declarations: `struct timerlat_aa_data`, `struct timerlat_aa_context`, `enum timelat_state`, `function timerlat_aa_irq_latency`, `function timerlat_aa_thread_latency`, `function timerlat_aa_handler`, `function timerlat_aa_nmi_handler`, `function timerlat_aa_irq_handler`, `function timerlat_aa_softirq_handler`, `function timerlat_aa_thread_handler`.
• 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.