tools/accounting/delaytop.c

Source file repositories/reference/linux-study-clean/tools/accounting/delaytop.c

File Facts

System: Linux kernel
Corpus path: tools/accounting/delaytop.c
Extension: .c
Size: 31548 bytes
Lines: 1146
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

stdio.h
stdlib.h
string.h
errno.h
unistd.h
fcntl.h
getopt.h
signal.h
time.h
dirent.h
ctype.h
stdbool.h
sys/types.h
sys/stat.h
sys/socket.h
sys/select.h
termios.h
limits.h
linux/genetlink.h
linux/taskstats.h
linux/cgroupstats.h
stddef.h

Detected Declarations

struct psi_stats
struct task_info
struct container_stats
struct field_desc
struct config
function enable_raw_mode
function disable_raw_mode
function display_available_fields
function usage
function parse_args
function set_mem_delay_total
function set_mem_count
function create_nl_socket
function send_cmd
function get_family_id
function read_psi_stats
function read_comm
function fetch_and_fill_task_info
function get_task_delays
function average_ms
function compare_tasks
function sort_tasks
function get_container_stats
function display_results
function check_for_keypress
function toggle_display_mode
function handle_keypress
function main

Annotated Snippet

struct psi_stats {
	double cpu_some_avg10, cpu_some_avg60, cpu_some_avg300;
	unsigned long long cpu_some_total;
	double cpu_full_avg10, cpu_full_avg60, cpu_full_avg300;
	unsigned long long cpu_full_total;
	double memory_some_avg10, memory_some_avg60, memory_some_avg300;
	unsigned long long memory_some_total;
	double memory_full_avg10, memory_full_avg60, memory_full_avg300;
	unsigned long long memory_full_total;
	double io_some_avg10, io_some_avg60, io_some_avg300;
	unsigned long long io_some_total;
	double io_full_avg10, io_full_avg60, io_full_avg300;
	unsigned long long io_full_total;
	double irq_full_avg10, irq_full_avg60, irq_full_avg300;
	unsigned long long irq_full_total;
};

/* Task delay information structure */
struct task_info {
	int pid;
	int tgid;
	char command[TASK_COMM_LEN];
	unsigned long long cpu_count;
	unsigned long long cpu_delay_total;
	unsigned long long blkio_count;
	unsigned long long blkio_delay_total;
	unsigned long long swapin_count;
	unsigned long long swapin_delay_total;
	unsigned long long freepages_count;
	unsigned long long freepages_delay_total;
	unsigned long long thrashing_count;
	unsigned long long thrashing_delay_total;
	unsigned long long compact_count;
	unsigned long long compact_delay_total;
	unsigned long long wpcopy_count;
	unsigned long long wpcopy_delay_total;
	unsigned long long irq_count;
	unsigned long long irq_delay_total;
	unsigned long long mem_count;
	unsigned long long mem_delay_total;
};

/* Container statistics structure */
struct container_stats {
	int nr_sleeping;		/* Number of sleeping processes */
	int nr_running;			/* Number of running processes */
	int nr_stopped;			/* Number of stopped processes */
	int nr_uninterruptible; /* Number of uninterruptible processes */
	int nr_io_wait;			/* Number of processes in IO wait */
};

/* Delay field structure */
struct field_desc {
	const char *name;	/* Field name for cmdline argument */
	const char *cmd_char;	/* Interactive command */
	unsigned long total_offset; /* Offset of total delay in task_info */
	unsigned long count_offset; /* Offset of count in task_info */
	size_t supported_modes; /* Supported display modes */
};

/* Program settings structure */
struct config {
	int delay;				/* Update interval in seconds */
	int iterations;			/* Number of iterations, 0 == infinite */
	int max_processes;		/* Maximum number of processes to show */
	int output_one_time;	/* Output once and exit */
	int monitor_pid;		/* Monitor specific PID */
	char *container_path;	/* Path to container cgroup */
	const struct field_desc *sort_field;	/* Current sort field */
	size_t display_mode;	/* Current display mode */
};

/* Global variables */
static struct config cfg;
static struct psi_stats psi;
static struct task_info tasks[MAX_TASKS];
static int task_count;
static int running = 1;
static struct container_stats container_stats;
static const struct field_desc sort_fields[] = {
	SORT_FIELD(cpu,		c,	MODE_DEFAULT),
	SORT_FIELD(blkio,	i,	MODE_DEFAULT),
	SORT_FIELD(irq,		q,	MODE_DEFAULT),
	SORT_FIELD(mem,		m,	MODE_DEFAULT | MODE_MEMVERBOSE),
	SORT_FIELD(swapin,	s,	MODE_MEMVERBOSE),
	SORT_FIELD(freepages,	r,	MODE_MEMVERBOSE),
	SORT_FIELD(thrashing,	t,	MODE_MEMVERBOSE),
	SORT_FIELD(compact,	p,	MODE_MEMVERBOSE),
	SORT_FIELD(wpcopy,	w,	MODE_MEMVERBOSE),
	END_FIELD

Annotation

Immediate include surface: `stdio.h`, `stdlib.h`, `string.h`, `errno.h`, `unistd.h`, `fcntl.h`, `getopt.h`, `signal.h`.
Detected declarations: `struct psi_stats`, `struct task_info`, `struct container_stats`, `struct field_desc`, `struct config`, `function enable_raw_mode`, `function disable_raw_mode`, `function display_available_fields`, `function usage`, `function parse_args`.
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.