path: root/tools/accounting/delaytop.c

// SPDX-License-Identifier: GPL-2.0
/*
 * delaytop.c - system-wide delay monitoring tool.
 *
 * This tool provides real-time monitoring and statistics of
 * system, container, and task-level delays, including CPU,
 * memory, IO, and IRQ. It supports both interactive (top-like),
 * and can output delay information for the whole system, specific
 * containers (cgroups), or individual tasks (PIDs).
 *
 * Key features:
 *	- Collects per-task delay accounting statistics via taskstats.
 *	- Collects system-wide PSI information.
 *	- Supports sorting, filtering.
 *	- Supports both interactive (screen refresh).
 *
 * Copyright (C) Fan Yu, ZTE Corp. 2025
 * Copyright (C) Wang Yaxin, ZTE Corp. 2025
 *
 * Compile with
 *	gcc -I/usr/src/linux/include delaytop.c -o delaytop
 */

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

#define PSI_PATH	"/proc/pressure"
#define PSI_CPU_PATH	"/proc/pressure/cpu"
#define PSI_MEMORY_PATH	"/proc/pressure/memory"
#define PSI_IO_PATH	"/proc/pressure/io"
#define PSI_IRQ_PATH	"/proc/pressure/irq"

#define NLA_NEXT(na)			((struct nlattr *)((char *)(na) + NLA_ALIGN((na)->nla_len)))
#define NLA_DATA(na)			((void *)((char *)(na) + NLA_HDRLEN))
#define NLA_PAYLOAD(len)		(len - NLA_HDRLEN)

#define GENLMSG_DATA(glh)		((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
#define GENLMSG_PAYLOAD(glh)	(NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)

#define TASK_COMM_LEN	16
#define MAX_MSG_SIZE	1024
#define MAX_TASKS		1000
#define MAX_BUF_LEN		256
#define SET_TASK_STAT(task_count, field) tasks[task_count].field = stats.field
#define BOOL_FPRINT(stream, fmt, ...) \
({ \
	int ret = fprintf(stream, fmt, ##__VA_ARGS__); \
	ret >= 0; \
})
#define TASK_AVG(task, field) average_ms((task).field##_delay_total, (task).field##_count)
#define PSI_LINE_FORMAT "%-12s %6.1f%%/%6.1f%%/%6.1f%%/%8llu(ms)\n"
#define DELAY_FMT_DEFAULT "%8.2f %8.2f %8.2f %8.2f\n"
#define DELAY_FMT_MEMVERBOSE "%8.2f %8.2f %8.2f %8.2f %8.2f %8.2f\n"
#define SORT_FIELD(name, cmd, modes) \
	{#name, #cmd, \
	offsetof(struct task_info, name##_delay_total), \
	offsetof(struct task_info, name##_count), \
	modes}
#define END_FIELD {NULL, 0, 0}

/* Display mode types */
#define MODE_TYPE_ALL	(0xFFFFFFFF)
#define MODE_DEFAULT	(1 << 0)
#define MODE_MEMVERBOSE	(1 << 1)

/* PSI statistics structure */
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 *