source: MondoRescue/branches/3.2/mindi-busybox/procps/iostat.c@ 3248

/* vi: set sw=4 ts=4: */
/*
 * Report CPU and I/O stats, based on sysstat version 9.1.2 by Sebastien Godard
 *
 * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

//config:config IOSTAT
//config:   bool "iostat"
//config:   default y
//config:   help
//config:     Report CPU and I/O statistics

//applet:IF_IOSTAT(APPLET(iostat, BB_DIR_BIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_IOSTAT) += iostat.o

#include "libbb.h"
#include <sys/utsname.h>  /* struct utsname */

//#define debug(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
#define debug(fmt, ...) ((void)0)

#define MAX_DEVICE_NAME 12
#define MAX_DEVICE_NAME_STR "12"

#if 1
typedef unsigned long long cputime_t;
typedef long long icputime_t;
# define FMT_DATA "ll"
# define CPUTIME_MAX (~0ULL)
#else
typedef unsigned long cputime_t;
typedef long icputime_t;
# define FMT_DATA "l"
# define CPUTIME_MAX (~0UL)
#endif

enum {
    STATS_CPU_USER,
    STATS_CPU_NICE,
    STATS_CPU_SYSTEM,
    STATS_CPU_IDLE,
    STATS_CPU_IOWAIT,
    STATS_CPU_IRQ,
    STATS_CPU_SOFTIRQ,
    STATS_CPU_STEAL,
    STATS_CPU_GUEST,

    GLOBAL_UPTIME,
    SMP_UPTIME,

    N_STATS_CPU,
};

typedef struct {
    cputime_t vector[N_STATS_CPU];
} stats_cpu_t;

typedef struct {
    stats_cpu_t *prev;
    stats_cpu_t *curr;
    cputime_t itv;
} stats_cpu_pair_t;

typedef struct {
    unsigned long long rd_sectors;
    unsigned long long wr_sectors;
    unsigned long rd_ops;
    unsigned long wr_ops;
} stats_dev_data_t;

typedef struct stats_dev {
    struct stats_dev *next;
    char dname[MAX_DEVICE_NAME + 1];
    stats_dev_data_t prev_data;
    stats_dev_data_t curr_data;
} stats_dev_t;

/* Globals. Sort by size and access frequency. */
struct globals {
    smallint show_all;
    unsigned total_cpus;            /* Number of CPUs */
    unsigned clk_tck;               /* Number of clock ticks per second */
    llist_t *dev_name_list;         /* List of devices entered on the command line */
    stats_dev_t *stats_dev_list;
    struct tm tmtime;
    struct {
        const char *str;
        unsigned div;
    } unit;
};
#define G (*ptr_to_globals)
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
    G.unit.str = "Blk"; \
    G.unit.div = 1; \
} while (0)

/* Must match option string! */
enum {
    OPT_c = 1 << 0,
    OPT_d = 1 << 1,
    OPT_t = 1 << 2,
    OPT_z = 1 << 3,
    OPT_k = 1 << 4,
    OPT_m = 1 << 5,
};

static ALWAYS_INLINE unsigned get_user_hz(void)
{
    return sysconf(_SC_CLK_TCK);
}

static ALWAYS_INLINE int this_is_smp(void)
{
    return (G.total_cpus > 1);
}

static void print_header(void)
{
    char buf[32];
    struct utsname uts;

    uname(&uts); /* never fails */

    /* Date representation for the current locale */
    strftime(buf, sizeof(buf), "%x", &G.tmtime);

    printf("%s %s (%s) \t%s \t_%s_\t(%u CPU)\n\n",
            uts.sysname, uts.release, uts.nodename,
            buf, uts.machine, G.total_cpus);
}

static void get_localtime(struct tm *ptm)
{
    time_t timer;
    time(&timer);
    localtime_r(&timer, ptm);
}

static void print_timestamp(void)
{
    char buf[64];
    /* %x: date representation for the current locale */
    /* %X: time representation for the current locale */
    strftime(buf, sizeof(buf), "%x %X", &G.tmtime);
    printf("%s\n", buf);
}

static cputime_t get_smp_uptime(void)
{
    FILE *fp;
    unsigned long sec, dec;

    fp = xfopen_for_read("/proc/uptime");

    if (fscanf(fp, "%lu.%lu", &sec, &dec) != 2)
        bb_error_msg_and_die("can't read '%s'", "/proc/uptime");

    fclose(fp);

    return (cputime_t)sec * G.clk_tck + dec * G.clk_tck / 100;
}

/* Fetch CPU statistics from /proc/stat */
static void get_cpu_statistics(stats_cpu_t *sc)
{
    FILE *fp;
    char buf[1024];

    fp = xfopen_for_read("/proc/stat");

    memset(sc, 0, sizeof(*sc));

    while (fgets(buf, sizeof(buf), fp)) {
        int i;
        char *ibuf;

        /* Does the line start with "cpu "? */
        if (!starts_with_cpu(buf) || buf[3] != ' ') {
            continue;
        }
        ibuf = buf + 4;
        for (i = STATS_CPU_USER; i <= STATS_CPU_GUEST; i++) {
            ibuf = skip_whitespace(ibuf);
            sscanf(ibuf, "%"FMT_DATA"u", &sc->vector[i]);
            if (i != STATS_CPU_GUEST) {
                sc->vector[GLOBAL_UPTIME] += sc->vector[i];
            }
            ibuf = skip_non_whitespace(ibuf);
        }
        break;
    }

    if (this_is_smp()) {
        sc->vector[SMP_UPTIME] = get_smp_uptime();
    }

    fclose(fp);
}

static ALWAYS_INLINE cputime_t get_interval(cputime_t old, cputime_t new)
{
    cputime_t itv = new - old;

    return (itv == 0) ? 1 : itv;
}

#if CPUTIME_MAX > 0xffffffff
/*
 * Handle overflow conditions properly for counters which can have
 * less bits than cputime_t, depending on the kernel version.
 */
/* Surprisingly, on 32bit inlining is a size win */
static ALWAYS_INLINE cputime_t overflow_safe_sub(cputime_t prev, cputime_t curr)
{
    cputime_t v = curr - prev;

    if ((icputime_t)v < 0     /* curr < prev - counter overflow? */
     && prev <= 0xffffffff /* kernel uses 32bit value for the counter? */
    ) {
        /* Add 33th bit set to 1 to curr, compensating for the overflow */
        /* double shift defeats "warning: left shift count >= width of type" */
        v += ((cputime_t)1 << 16) << 16;
    }
    return v;
}
#else
static ALWAYS_INLINE cputime_t overflow_safe_sub(cputime_t prev, cputime_t curr)
{
    return curr - prev;
}
#endif

static double percent_value(cputime_t prev, cputime_t curr, cputime_t itv)
{
    return ((double)overflow_safe_sub(prev, curr)) / itv * 100;
}

static void print_stats_cpu_struct(stats_cpu_pair_t *stats)
{
    cputime_t *p = stats->prev->vector;
    cputime_t *c = stats->curr->vector;
    printf("        %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",
        percent_value(p[STATS_CPU_USER]  , c[STATS_CPU_USER]  , stats->itv),
        percent_value(p[STATS_CPU_NICE]  , c[STATS_CPU_NICE]  , stats->itv),
        percent_value(p[STATS_CPU_SYSTEM] + p[STATS_CPU_SOFTIRQ] + p[STATS_CPU_IRQ],
            c[STATS_CPU_SYSTEM] + c[STATS_CPU_SOFTIRQ] + c[STATS_CPU_IRQ], stats->itv),
        percent_value(p[STATS_CPU_IOWAIT], c[STATS_CPU_IOWAIT], stats->itv),
        percent_value(p[STATS_CPU_STEAL] , c[STATS_CPU_STEAL] , stats->itv),
        percent_value(p[STATS_CPU_IDLE]  , c[STATS_CPU_IDLE]  , stats->itv)
    );
}

static void cpu_report(stats_cpu_pair_t *stats)
{
    /* Always print a header */
    puts("avg-cpu:  %user   %nice %system %iowait  %steal   %idle");

    /* Print current statistics */
    print_stats_cpu_struct(stats);
}

static void print_stats_dev_struct(stats_dev_t *stats_dev, cputime_t itv)
{
    stats_dev_data_t *p = &stats_dev->prev_data;
    stats_dev_data_t *c = &stats_dev->curr_data;
    if (option_mask32 & OPT_z)
        if (p->rd_ops == c->rd_ops && p->wr_ops == c->wr_ops)
            return;

    printf("%-13s %8.2f %12.2f %12.2f %10llu %10llu\n",
        stats_dev->dname,
        percent_value(p->rd_ops + p->wr_ops, c->rd_ops + c->wr_ops, itv),
        percent_value(p->rd_sectors, c->rd_sectors, itv) / G.unit.div,
        percent_value(p->wr_sectors, c->wr_sectors, itv) / G.unit.div,
        (c->rd_sectors - p->rd_sectors) / G.unit.div,
        (c->wr_sectors - p->wr_sectors) / G.unit.div
    );
}

static void print_devstat_header(void)
{
    printf("Device:%15s%6s%s/s%6s%s/s%6s%s%6s%s\n",
        "tps",
        G.unit.str, "_read", G.unit.str, "_wrtn",
        G.unit.str, "_read", G.unit.str, "_wrtn"
    );
}

/*
 * Is input partition of format [sdaN]?
 */
static int is_partition(const char *dev)
{
    /* Ok, this is naive... */
    return ((dev[0] - 's') | (dev[1] - 'd') | (dev[2] - 'a')) == 0 && isdigit(dev[3]);
}

static stats_dev_t *stats_dev_find_or_new(const char *dev_name)
{
    stats_dev_t **curr = &G.stats_dev_list;

    while (*curr != NULL) {
        if (strcmp((*curr)->dname, dev_name) == 0)
            return *curr;
        curr = &(*curr)->next;
    }

    *curr = xzalloc(sizeof(stats_dev_t));
    strncpy((*curr)->dname, dev_name, MAX_DEVICE_NAME);
    return *curr;
}

static void stats_dev_free(stats_dev_t *stats_dev)
{
    if (stats_dev) {
        stats_dev_free(stats_dev->next);
        free(stats_dev);
    }
}

static void do_disk_statistics(cputime_t itv)
{
    char buf[128];
    char dev_name[MAX_DEVICE_NAME + 1];
    unsigned long long rd_sec_or_dummy;
    unsigned long long wr_sec_or_dummy;
    stats_dev_data_t *curr_data;
    stats_dev_t *stats_dev;
    FILE *fp;
    int rc;

    fp = xfopen_for_read("/proc/diskstats");
    /* Read and possibly print stats from /proc/diskstats */
    while (fgets(buf, sizeof(buf), fp)) {
        sscanf(buf, "%*s %*s %"MAX_DEVICE_NAME_STR"s", dev_name);
        if (G.dev_name_list) {
            /* Is device name in list? */
            if (!llist_find_str(G.dev_name_list, dev_name))
                continue;
        } else if (is_partition(dev_name)) {
            continue;
        }

        stats_dev = stats_dev_find_or_new(dev_name);
        curr_data = &stats_dev->curr_data;

        rc = sscanf(buf, "%*s %*s %*s %lu %llu %llu %llu %lu %*s %llu",
            &curr_data->rd_ops,
            &rd_sec_or_dummy,
            &curr_data->rd_sectors,
            &wr_sec_or_dummy,
            &curr_data->wr_ops,
            &curr_data->wr_sectors);
        if (rc != 6) {
            curr_data->rd_sectors = rd_sec_or_dummy;
            curr_data->wr_sectors = wr_sec_or_dummy;
            //curr_data->rd_ops = ;
            curr_data->wr_ops = (unsigned long)curr_data->rd_sectors;
        }

        if (!G.dev_name_list /* User didn't specify device */
         && !G.show_all
         && curr_data->rd_ops == 0
         && curr_data->wr_ops == 0
        ) {
            /* Don't print unused device */
            continue;
        }

        /* Print current statistics */
        print_stats_dev_struct(stats_dev, itv);
        stats_dev->prev_data = *curr_data;
    }

    fclose(fp);
}

static void dev_report(cputime_t itv)
{
    /* Always print a header */
    print_devstat_header();

    /* Fetch current disk statistics */
    do_disk_statistics(itv);
}

//usage:#define iostat_trivial_usage
//usage:       "[-c] [-d] [-t] [-z] [-k|-m] [ALL|BLOCKDEV...] [INTERVAL [COUNT]]"
//usage:#define iostat_full_usage "\n\n"
//usage:       "Report CPU and I/O statistics\n"
//usage:     "\n    -c  Show CPU utilization"
//usage:     "\n    -d  Show device utilization"
//usage:     "\n    -t  Print current time"
//usage:     "\n    -z  Omit devices with no activity"
//usage:     "\n    -k  Use kb/s"
//usage:     "\n    -m  Use Mb/s"

int iostat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int iostat_main(int argc UNUSED_PARAM, char **argv)
{
    int opt;
    unsigned interval;
    int count;
    stats_cpu_t stats_data[2];
    smallint current_stats;

    INIT_G();

    memset(&stats_data, 0, sizeof(stats_data));

    /* Get number of clock ticks per sec */
    G.clk_tck = get_user_hz();

    /* Determine number of CPUs */
    G.total_cpus = get_cpu_count();
    if (G.total_cpus == 0)
        G.total_cpus = 1;

    /* Parse and process arguments */
    /* -k and -m are mutually exclusive */
    opt_complementary = "k--m:m--k";
    opt = getopt32(argv, "cdtzkm");
    if (!(opt & (OPT_c + OPT_d)))
        /* Default is -cd */
        opt |= OPT_c + OPT_d;

    argv += optind;

    /* Store device names into device list */
    while (*argv && !isdigit(*argv[0])) {
        if (strcmp(*argv, "ALL") != 0) {
            /* If not ALL, save device name */
            char *dev_name = skip_dev_pfx(*argv);
            if (!llist_find_str(G.dev_name_list, dev_name)) {
                llist_add_to(&G.dev_name_list, dev_name);
            }
        } else {
            G.show_all = 1;
        }
        argv++;
    }

    interval = 0;
    count = 1;
    if (*argv) {
        /* Get interval */
        interval = xatoi_positive(*argv);
        count = (interval != 0 ? -1 : 1);
        argv++;
        if (*argv)
            /* Get count value */
            count = xatoi_positive(*argv);
    }

    if (opt & OPT_m) {
        G.unit.str = " MB";
        G.unit.div = 2048;
    }

    if (opt & OPT_k) {
        G.unit.str = " kB";
        G.unit.div = 2;
    }

    get_localtime(&G.tmtime);

    /* Display header */
    print_header();

    current_stats = 0;
    /* Main loop */
    for (;;) {
        stats_cpu_pair_t stats;

        stats.prev = &stats_data[current_stats ^ 1];
        stats.curr = &stats_data[current_stats];

        /* Fill the time structure */
        get_localtime(&G.tmtime);

        /* Fetch current CPU statistics */
        get_cpu_statistics(stats.curr);

        /* Get interval */
        stats.itv = get_interval(
            stats.prev->vector[GLOBAL_UPTIME],
            stats.curr->vector[GLOBAL_UPTIME]
        );

        if (opt & OPT_t)
            print_timestamp();

        if (opt & OPT_c) {
            cpu_report(&stats);
            if (opt & OPT_d)
                /* Separate outputs by a newline */
                bb_putchar('\n');
        }

        if (opt & OPT_d) {
            if (this_is_smp()) {
                stats.itv = get_interval(
                    stats.prev->vector[SMP_UPTIME],
                    stats.curr->vector[SMP_UPTIME]
                );
            }
            dev_report(stats.itv);
        }

        bb_putchar('\n');

        if (count > 0) {
            if (--count == 0)
                break;
        }

        /* Swap stats */
        current_stats ^= 1;

        sleep(interval);
    }

    if (ENABLE_FEATURE_CLEAN_UP) {
        llist_free(G.dev_name_list, NULL);
        stats_dev_free(G.stats_dev_list);
        free(&G);
    }

    return EXIT_SUCCESS;
}