From: Yaxin Wang Date: Thu, 19 Jun 2025 13:18:43 +0000 (+0800) Subject: tools/accounting/delaytop: add delaytop to record top-n task delay X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=01bda05819b89b38eebad7e2034b8ab14eee5207;p=thirdparty%2Flinux.git tools/accounting/delaytop: add delaytop to record top-n task delay Problem ======= The "getdelays" can only display the latency of a single task by specifying a PID, but it has the following limitations: 1. single-task perspective: only supports querying the latency (CPU, I/O, memory, etc.) of an individual task via PID and cannot provide a global analysis of high-latency processes across the system. 2. lack of High-Latency process awareness: when the overall system latency is high (e.g., a spike in CPU latency), there is no way to quickly identify the top N processes contributing to the highest latency. 3. poor interactivity: It lacks dynamic sorting and refresh capabilities (similar to top), making it difficult to monitor latency changes in real time. Solution ======== To address these limitations, we introduce the "delaytop" with the following capabilities: 1. system view: monitors latency metrics (CPU, I/O, memory, IRQ, etc.) for all system processes 2. supports field-based sorting (e.g., default sort by CPU latency in descending order) 3. dynamic interactive interface: focus on specific processes with --pid; limit displayed entries with --processes 20; control monitoring duration with --iterations; Use case ======== bash# ./delaytop Top 20 processes (sorted by CPU delay): PID TGID COMMAND CPU(ms) IO(ms) SWAP(ms) RCL(ms) THR(ms) CMP(ms) WP(ms) IRQ(ms) --------------------------------------------------------------------------------------------- 26 26 kworker/1:0H 5.55 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32 32 kworker/2:0H-kb 2.93 0.00 0.00 0.00 0.00 0.00 0.00 0.00 38 38 kworker/3:0H-ev 2.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 84 84 kworker/R-vfio- 1.62 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24 24 ksoftirqd/1 1.43 0.00 0.00 0.00 0.00 0.00 0.00 0.00 19 19 idle_inject/0 0.99 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16 16 rcu_exp_par_gp_ 0.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 11 11 kworker/0:1 0.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 22 22 idle_inject/1 0.80 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3 3 pool_workqueue_ 0.74 0.00 0.00 0.00 0.00 0.00 0.00 0.00 81 81 scsi_eh_1 0.59 0.00 0.00 0.00 0.00 0.00 0.00 0.00 30 30 ksoftirqd/2 0.42 0.00 0.00 0.00 0.00 0.00 0.00 0.00 36 36 ksoftirqd/3 0.37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 9 9 kworker/0:0-eve 0.36 0.00 0.00 0.00 0.00 0.00 0.00 0.00 8 8 kworker/R-netns 0.34 0.00 0.00 0.00 0.00 0.00 0.00 0.00 76 76 kworker/1:1-pm 0.32 0.00 0.00 0.00 0.00 0.00 0.00 0.00 21 21 cpuhp/1 0.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4 4 kworker/R-rcu_g 0.21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 12 12 kworker/u16:0-i 0.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 1 init 0.18 0.00 0.00 0.00 0.00 0.00 0.08 0.00 Link: https://lkml.kernel.org/r/20250619211843633h05gWrBDMFkEH6xAVm_5y@zte.com.cn Co-developed-by: Fan Yu Signed-off-by: Fan Yu Signed-off-by: Yaxin Wang Cc: Balbir Singh Cc: David Hildenbrand Cc: Peilin He Cc: Qiang Tu Cc: wangyong Cc: xu xin Cc: Yang Yang Cc: ye xingchen Cc: Yunkai Zhang Signed-off-by: Andrew Morton --- diff --git a/tools/accounting/Makefile b/tools/accounting/Makefile index 11def1ad046c8..20bbd461515e5 100644 --- a/tools/accounting/Makefile +++ b/tools/accounting/Makefile @@ -2,7 +2,7 @@ CC := $(CROSS_COMPILE)gcc CFLAGS := -I../../usr/include -PROGS := getdelays procacct +PROGS := getdelays procacct delaytop all: $(PROGS) diff --git a/tools/accounting/delaytop.c b/tools/accounting/delaytop.c new file mode 100644 index 0000000000000..23e38f39e97d0 --- /dev/null +++ b/tools/accounting/delaytop.c @@ -0,0 +1,673 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * delaytop.c - task delay monitoring tool. + * + * This tool provides real-time monitoring and statistics of + * system, container, and task-level delays, including CPU, + * memory, IO, and IRQ and delay accounting. 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. + * - 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 SET_TASK_STAT(task_count, field) tasks[task_count].field = stats.field + +/* 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 */ + char sort_field; /* Field to sort by */ + int output_one_time; /* Output once and exit */ + int monitor_pid; /* Monitor specific PID */ + char *container_path; /* Path to container cgroup */ +}; + +/* 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; +}; + +/* 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 */ +}; + +/* Global variables */ +static struct config cfg; +static struct task_info tasks[MAX_TASKS]; +static int task_count; +static int running = 1; +static struct container_stats container_stats; + +/* Netlink socket variables */ +static int nl_sd = -1; +static int family_id; + +/* Set terminal to non-canonical mode for q-to-quit */ +static struct termios orig_termios; +static void enable_raw_mode(void) +{ + struct termios raw; + + tcgetattr(STDIN_FILENO, &orig_termios); + raw = orig_termios; + raw.c_lflag &= ~(ICANON | ECHO); + tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw); +} +static void disable_raw_mode(void) +{ + tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios); +} + +/* Display usage information and command line options */ +static void usage(void) +{ + printf("Usage: delaytop [Options]\n" + "Options:\n" + " -h, --help Show this help message and exit\n" + " -d, --delay=SECONDS Set refresh interval (default: 2 seconds, min: 1)\n" + " -n, --iterations=COUNT Set number of updates (default: 0 = infinite)\n" + " -P, --processes=NUMBER Set maximum number of processes to show (default: 20, max: 1000)\n" + " -o, --once Display once and exit\n" + " -p, --pid=PID Monitor only the specified PID\n" + " -C, --container=PATH Monitor the container at specified cgroup path\n"); + exit(0); +} + +/* Parse command line arguments and set configuration */ +static void parse_args(int argc, char **argv) +{ + int c; + struct option long_options[] = { + {"help", no_argument, 0, 'h'}, + {"delay", required_argument, 0, 'd'}, + {"iterations", required_argument, 0, 'n'}, + {"pid", required_argument, 0, 'p'}, + {"once", no_argument, 0, 'o'}, + {"processes", required_argument, 0, 'P'}, + {"container", required_argument, 0, 'C'}, + {0, 0, 0, 0} + }; + + /* Set defaults */ + cfg.delay = 2; + cfg.iterations = 0; + cfg.max_processes = 20; + cfg.sort_field = 'c'; /* Default sort by CPU delay */ + cfg.output_one_time = 0; + cfg.monitor_pid = 0; /* 0 means monitor all PIDs */ + cfg.container_path = NULL; + + while (1) { + int option_index = 0; + + c = getopt_long(argc, argv, "hd:n:p:oP:C:", long_options, &option_index); + if (c == -1) + break; + + switch (c) { + case 'h': + usage(); + break; + case 'd': + cfg.delay = atoi(optarg); + if (cfg.delay < 1) { + fprintf(stderr, "Error: delay must be >= 1.\n"); + exit(1); + } + break; + case 'n': + cfg.iterations = atoi(optarg); + if (cfg.iterations < 0) { + fprintf(stderr, "Error: iterations must be >= 0.\n"); + exit(1); + } + break; + case 'p': + cfg.monitor_pid = atoi(optarg); + if (cfg.monitor_pid < 1) { + fprintf(stderr, "Error: pid must be >= 1.\n"); + exit(1); + } + break; + case 'o': + cfg.output_one_time = 1; + break; + case 'P': + cfg.max_processes = atoi(optarg); + if (cfg.max_processes < 1) { + fprintf(stderr, "Error: processes must be >= 1.\n"); + exit(1); + } + if (cfg.max_processes > MAX_TASKS) { + fprintf(stderr, "Warning: processes capped to %d.\n", + MAX_TASKS); + cfg.max_processes = MAX_TASKS; + } + break; + case 'C': + cfg.container_path = strdup(optarg); + break; + default: + fprintf(stderr, "Try 'delaytop --help' for more information.\n"); + exit(1); + } + } +} + +/* Create a raw netlink socket and bind */ +static int create_nl_socket(void) +{ + int fd; + struct sockaddr_nl local; + + fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); + if (fd < 0) + return -1; + + memset(&local, 0, sizeof(local)); + local.nl_family = AF_NETLINK; + + if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0) { + close(fd); + return -1; + } + + return fd; +} + +/* Send a command via netlink */ +static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid, + __u8 genl_cmd, __u16 nla_type, + void *nla_data, int nla_len) +{ + struct sockaddr_nl nladdr; + struct nlattr *na; + int r, buflen; + char *buf; + + struct { + struct nlmsghdr n; + struct genlmsghdr g; + char buf[MAX_MSG_SIZE]; + } msg; + + msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN); + msg.n.nlmsg_type = nlmsg_type; + msg.n.nlmsg_flags = NLM_F_REQUEST; + msg.n.nlmsg_seq = 0; + msg.n.nlmsg_pid = nlmsg_pid; + msg.g.cmd = genl_cmd; + msg.g.version = 0x1; + na = (struct nlattr *) GENLMSG_DATA(&msg); + na->nla_type = nla_type; + na->nla_len = nla_len + NLA_HDRLEN; + memcpy(NLA_DATA(na), nla_data, nla_len); + msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len); + + buf = (char *) &msg; + buflen = msg.n.nlmsg_len; + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr, + sizeof(nladdr))) < buflen) { + if (r > 0) { + buf += r; + buflen -= r; + } else if (errno != EAGAIN) + return -1; + } + return 0; +} + +/* Get family ID for taskstats via netlink */ +static int get_family_id(int sd) +{ + struct { + struct nlmsghdr n; + struct genlmsghdr g; + char buf[256]; + } ans; + + int id = 0, rc; + struct nlattr *na; + int rep_len; + char name[100]; + + strncpy(name, TASKSTATS_GENL_NAME, sizeof(name) - 1); + name[sizeof(name) - 1] = '\0'; + rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY, + CTRL_ATTR_FAMILY_NAME, (void *)name, + strlen(TASKSTATS_GENL_NAME)+1); + if (rc < 0) + return 0; + + rep_len = recv(sd, &ans, sizeof(ans), 0); + if (ans.n.nlmsg_type == NLMSG_ERROR || + (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len)) + return 0; + + na = (struct nlattr *) GENLMSG_DATA(&ans); + na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len)); + if (na->nla_type == CTRL_ATTR_FAMILY_ID) + id = *(__u16 *) NLA_DATA(na); + return id; +} + +static int read_comm(int pid, char *comm_buf, size_t buf_size) +{ + char path[64]; + size_t len; + FILE *fp; + + snprintf(path, sizeof(path), "/proc/%d/comm", pid); + fp = fopen(path, "r"); + if (!fp) + return -1; + if (fgets(comm_buf, buf_size, fp)) { + len = strlen(comm_buf); + if (len > 0 && comm_buf[len - 1] == '\n') + comm_buf[len - 1] = '\0'; + } else { + fclose(fp); + return -1; + } + fclose(fp); + return 0; +} + +static int fetch_and_fill_task_info(int pid, const char *comm) +{ + struct { + struct nlmsghdr n; + struct genlmsghdr g; + char buf[MAX_MSG_SIZE]; + } resp; + struct taskstats stats; + struct nlattr *nested; + struct nlattr *na; + int nested_len; + int nl_len; + int rc; + + if (send_cmd(nl_sd, family_id, getpid(), TASKSTATS_CMD_GET, + TASKSTATS_CMD_ATTR_PID, &pid, sizeof(pid)) < 0) { + return -1; + } + rc = recv(nl_sd, &resp, sizeof(resp), 0); + if (rc < 0 || resp.n.nlmsg_type == NLMSG_ERROR) + return -1; + nl_len = GENLMSG_PAYLOAD(&resp.n); + na = (struct nlattr *) GENLMSG_DATA(&resp); + while (nl_len > 0) { + if (na->nla_type == TASKSTATS_TYPE_AGGR_PID) { + nested = (struct nlattr *) NLA_DATA(na); + nested_len = NLA_PAYLOAD(na->nla_len); + while (nested_len > 0) { + if (nested->nla_type == TASKSTATS_TYPE_STATS) { + memcpy(&stats, NLA_DATA(nested), sizeof(stats)); + if (task_count < MAX_TASKS) { + tasks[task_count].pid = pid; + tasks[task_count].tgid = pid; + strncpy(tasks[task_count].command, comm, + TASK_COMM_LEN - 1); + tasks[task_count].command[TASK_COMM_LEN - 1] = '\0'; + SET_TASK_STAT(task_count, cpu_count); + SET_TASK_STAT(task_count, cpu_delay_total); + SET_TASK_STAT(task_count, blkio_count); + SET_TASK_STAT(task_count, blkio_delay_total); + SET_TASK_STAT(task_count, swapin_count); + SET_TASK_STAT(task_count, swapin_delay_total); + SET_TASK_STAT(task_count, freepages_count); + SET_TASK_STAT(task_count, freepages_delay_total); + SET_TASK_STAT(task_count, thrashing_count); + SET_TASK_STAT(task_count, thrashing_delay_total); + SET_TASK_STAT(task_count, compact_count); + SET_TASK_STAT(task_count, compact_delay_total); + SET_TASK_STAT(task_count, wpcopy_count); + SET_TASK_STAT(task_count, wpcopy_delay_total); + SET_TASK_STAT(task_count, irq_count); + SET_TASK_STAT(task_count, irq_delay_total); + task_count++; + } + break; + } + nested_len -= NLA_ALIGN(nested->nla_len); + nested = NLA_NEXT(nested); + } + } + nl_len -= NLA_ALIGN(na->nla_len); + na = NLA_NEXT(na); + } + return 0; +} + +static void get_task_delays(void) +{ + char comm[TASK_COMM_LEN]; + struct dirent *entry; + DIR *dir; + int pid; + + task_count = 0; + if (cfg.monitor_pid > 0) { + if (read_comm(cfg.monitor_pid, comm, sizeof(comm)) == 0) + fetch_and_fill_task_info(cfg.monitor_pid, comm); + return; + } + + dir = opendir("/proc"); + if (!dir) { + fprintf(stderr, "Error opening /proc directory\n"); + return; + } + + while ((entry = readdir(dir)) != NULL && task_count < MAX_TASKS) { + if (!isdigit(entry->d_name[0])) + continue; + pid = atoi(entry->d_name); + if (pid == 0) + continue; + if (read_comm(pid, comm, sizeof(comm)) != 0) + continue; + fetch_and_fill_task_info(pid, comm); + } + closedir(dir); +} + +/* Calculate average delay in milliseconds */ +static double average_ms(unsigned long long total, unsigned long long count) +{ + if (count == 0) + return 0; + return (double)total / 1000000.0 / count; +} + +/* Comparison function for sorting tasks */ +static int compare_tasks(const void *a, const void *b) +{ + const struct task_info *t1 = (const struct task_info *)a; + const struct task_info *t2 = (const struct task_info *)b; + double avg1, avg2; + + switch (cfg.sort_field) { + case 'c': /* CPU */ + avg1 = average_ms(t1->cpu_delay_total, t1->cpu_count); + avg2 = average_ms(t2->cpu_delay_total, t2->cpu_count); + if (avg1 != avg2) + return avg2 > avg1 ? 1 : -1; + return t2->cpu_delay_total > t1->cpu_delay_total ? 1 : -1; + + default: + return t2->cpu_delay_total > t1->cpu_delay_total ? 1 : -1; + } +} + +/* Sort tasks by selected field */ +static void sort_tasks(void) +{ + if (task_count > 0) + qsort(tasks, task_count, sizeof(struct task_info), compare_tasks); +} + +/* Get container statistics via cgroupstats */ +static void get_container_stats(void) +{ + int rc, cfd; + struct { + struct nlmsghdr n; + struct genlmsghdr g; + char buf[MAX_MSG_SIZE]; + } req, resp; + struct nlattr *na; + int nl_len; + struct cgroupstats stats; + + /* Check if container path is set */ + if (!cfg.container_path) + return; + + /* Open container cgroup */ + cfd = open(cfg.container_path, O_RDONLY); + if (cfd < 0) { + fprintf(stderr, "Error opening container path: %s\n", cfg.container_path); + return; + } + + /* Send request for container stats */ + if (send_cmd(nl_sd, family_id, getpid(), CGROUPSTATS_CMD_GET, + CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32)) < 0) { + fprintf(stderr, "Failed to send request for container stats\n"); + close(cfd); + return; + } + + /* Receive response */ + rc = recv(nl_sd, &resp, sizeof(resp), 0); + if (rc < 0 || resp.n.nlmsg_type == NLMSG_ERROR) { + fprintf(stderr, "Failed to receive response for container stats\n"); + close(cfd); + return; + } + + /* Parse response */ + nl_len = GENLMSG_PAYLOAD(&resp.n); + na = (struct nlattr *) GENLMSG_DATA(&resp); + while (nl_len > 0) { + if (na->nla_type == CGROUPSTATS_TYPE_CGROUP_STATS) { + /* Get the cgroupstats structure */ + memcpy(&stats, NLA_DATA(na), sizeof(stats)); + + /* Fill container stats */ + container_stats.nr_sleeping = stats.nr_sleeping; + container_stats.nr_running = stats.nr_running; + container_stats.nr_stopped = stats.nr_stopped; + container_stats.nr_uninterruptible = stats.nr_uninterruptible; + container_stats.nr_io_wait = stats.nr_io_wait; + break; + } + nl_len -= NLA_ALIGN(na->nla_len); + na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len)); + } + + close(cfd); +} + +/* Display results to stdout or log file */ +static void display_results(void) +{ + time_t now = time(NULL); + struct tm *tm_now = localtime(&now); + char timestamp[32]; + int i, count; + FILE *out = stdout; + + fprintf(out, "\033[H\033[J"); + + if (cfg.container_path) { + fprintf(out, "Container Information (%s):\n", cfg.container_path); + fprintf(out, "Processes: running=%d, sleeping=%d, ", + container_stats.nr_running, container_stats.nr_sleeping); + fprintf(out, "stopped=%d, uninterruptible=%d, io_wait=%d\n\n", + container_stats.nr_stopped, container_stats.nr_uninterruptible, + container_stats.nr_io_wait); + } + fprintf(out, "Top %d processes (sorted by CPU delay):\n\n", + cfg.max_processes); + fprintf(out, " PID TGID COMMAND CPU(ms) IO(ms) "); + fprintf(out, "SWAP(ms) RCL(ms) THR(ms) CMP(ms) WP(ms) IRQ(ms)\n"); + fprintf(out, "-----------------------------------------------"); + fprintf(out, "----------------------------------------------\n"); + count = task_count < cfg.max_processes ? task_count : cfg.max_processes; + + for (i = 0; i < count; i++) { + fprintf(out, "%5d %5d %-15s ", + tasks[i].pid, tasks[i].tgid, tasks[i].command); + fprintf(out, "%7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n", + average_ms(tasks[i].cpu_delay_total, tasks[i].cpu_count), + average_ms(tasks[i].blkio_delay_total, tasks[i].blkio_count), + average_ms(tasks[i].swapin_delay_total, tasks[i].swapin_count), + average_ms(tasks[i].freepages_delay_total, tasks[i].freepages_count), + average_ms(tasks[i].thrashing_delay_total, tasks[i].thrashing_count), + average_ms(tasks[i].compact_delay_total, tasks[i].compact_count), + average_ms(tasks[i].wpcopy_delay_total, tasks[i].wpcopy_count), + average_ms(tasks[i].irq_delay_total, tasks[i].irq_count)); + } + + fprintf(out, "\n"); +} + +/* Main function */ +int main(int argc, char **argv) +{ + int iterations = 0; + int use_q_quit = 0; + + /* Parse command line arguments */ + parse_args(argc, argv); + + /* Setup netlink socket */ + nl_sd = create_nl_socket(); + if (nl_sd < 0) { + fprintf(stderr, "Error creating netlink socket\n"); + exit(1); + } + + /* Get family ID for taskstats via netlink */ + family_id = get_family_id(nl_sd); + if (!family_id) { + fprintf(stderr, "Error getting taskstats family ID\n"); + close(nl_sd); + exit(1); + } + + if (!cfg.output_one_time) { + use_q_quit = 1; + enable_raw_mode(); + printf("Press 'q' to quit.\n"); + fflush(stdout); + } + + /* Main loop */ + while (running) { + /* Get container stats if container path provided */ + if (cfg.container_path) + get_container_stats(); + + /* Get task delays */ + get_task_delays(); + + /* Sort tasks */ + sort_tasks(); + + /* Display results to stdout or log file */ + display_results(); + + /* Check for iterations */ + if (cfg.iterations > 0 && ++iterations >= cfg.iterations) + break; + + /* Exit if output_one_time is set */ + if (cfg.output_one_time) + break; + + /* Check for 'q' key to quit */ + if (use_q_quit) { + struct timeval tv = {cfg.delay, 0}; + fd_set readfds; + + FD_ZERO(&readfds); + FD_SET(STDIN_FILENO, &readfds); + int r = select(STDIN_FILENO+1, &readfds, NULL, NULL, &tv); + + if (r > 0 && FD_ISSET(STDIN_FILENO, &readfds)) { + char ch = 0; + + read(STDIN_FILENO, &ch, 1); + if (ch == 'q' || ch == 'Q') { + running = 0; + break; + } + } + } else { + sleep(cfg.delay); + } + } + + /* Restore terminal mode */ + if (use_q_quit) + disable_raw_mode(); + + /* Cleanup */ + close(nl_sd); + if (cfg.container_path) + free(cfg.container_path); + + return 0; +}