tools/tracing/rtla/src/timerlat_hist.c

File Facts

System

Linux kernel

Corpus path

tools/tracing/rtla/src/timerlat_hist.c

Extension

.c

Size

19464 bytes

Lines

790

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
• string.h
• signal.h
• unistd.h
• stdio.h
• time.h
• sched.h
• pthread.h
• timerlat.h
• timerlat_aa.h
• timerlat_bpf.h
• cli.h
• common.h

Detected Declarations

• struct timerlat_hist_cpu
• struct timerlat_hist_data
• function timerlat_free_histogram
• function timerlat_free_histogram_tool
• function timerlat_hist_update
• function timerlat_hist_handler
• function timerlat_hist_bpf_pull_data
• function timerlat_hist_header
• function for_each_monitored_cpu
• function format_summary_value
• function timerlat_print_summary
• function for_each_monitored_cpu
• function for_each_monitored_cpu
• function for_each_monitored_cpu
• function for_each_monitored_cpu
• function timerlat_print_stats_all
• function for_each_monitored_cpu
• function timerlat_print_stats
• function for_each_monitored_cpu
• function for_each_monitored_cpu
• function timerlat_hist_apply_config
• function timerlat_hist_bpf_main_loop
• function timerlat_hist_main

Annotated Snippet

struct timerlat_hist_cpu {
	int			*irq;
	int			*thread;
	int			*user;

	unsigned long long	irq_count;
	unsigned long long	thread_count;
	unsigned long long	user_count;

	unsigned long long	min_irq;
	unsigned long long	sum_irq;
	unsigned long long	max_irq;

	unsigned long long	min_thread;
	unsigned long long	sum_thread;
	unsigned long long	max_thread;

	unsigned long long	min_user;
	unsigned long long	sum_user;
	unsigned long long	max_user;
};

struct timerlat_hist_data {
	struct timerlat_hist_cpu	*hist;
	int				entries;
	int				bucket_size;
};

/*
 * timerlat_free_histogram - free runtime data
 */
static void
timerlat_free_histogram(struct timerlat_hist_data *data)
{
	int cpu;

	/* one histogram for IRQ and one for thread, per CPU */
	for (cpu = 0; cpu < nr_cpus; cpu++) {
		if (data->hist[cpu].irq)
			free(data->hist[cpu].irq);

		if (data->hist[cpu].thread)
			free(data->hist[cpu].thread);

		if (data->hist[cpu].user)
			free(data->hist[cpu].user);

	}

	/* one set of histograms per CPU */
	if (data->hist)
		free(data->hist);
}

static void timerlat_free_histogram_tool(struct osnoise_tool *tool)
{
	timerlat_free_histogram(tool->data);
	timerlat_free(tool);
}

/*
 * timerlat_alloc_histogram - alloc runtime data
 */
static struct timerlat_hist_data
*timerlat_alloc_histogram(int entries, int bucket_size)
{
	struct timerlat_hist_data *data;
	int cpu;

	data = calloc(1, sizeof(*data));
	if (!data)
		return NULL;

	data->entries = entries;
	data->bucket_size = bucket_size;

	/* one set of histograms per CPU */
	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
	if (!data->hist)
		goto cleanup;

	/* one histogram for IRQ and one for thread, per cpu */
	for (cpu = 0; cpu < nr_cpus; cpu++) {
		data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
		if (!data->hist[cpu].irq)
			goto cleanup;

		data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
		if (!data->hist[cpu].thread)
			goto cleanup;

Annotation

• Immediate include surface: `stdlib.h`, `string.h`, `signal.h`, `unistd.h`, `stdio.h`, `time.h`, `sched.h`, `pthread.h`.
• Detected declarations: `struct timerlat_hist_cpu`, `struct timerlat_hist_data`, `function timerlat_free_histogram`, `function timerlat_free_histogram_tool`, `function timerlat_hist_update`, `function timerlat_hist_handler`, `function timerlat_hist_bpf_pull_data`, `function timerlat_hist_header`, `function for_each_monitored_cpu`, `function format_summary_value`.
• 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.