busybox/procps/iostat.c
Maksym Kryzhanovskyy 29c54aa9f9 iostat: code shrink ~0.5k
Signed-off-by: Maksym Kryzhanovskyy <xmaks@email.cz>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-05-07 04:37:22 +02:00

540 lines
12 KiB
C

/* 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.
*/
//applet:IF_IOSTAT(APPLET(iostat, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_IOSTAT) += iostat.o
//config:config IOSTAT
//config: bool "iostat"
//config: default y
//config: help
//config: Report CPU and I/O statistics
#include "libbb.h"
#include <sys/utsname.h> /* Need struct utsname */
//#define debug(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
#define debug(fmt, ...) ((void)0)
#define MAX_DEVICE_NAME 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;
struct stats_dev {
char dname[MAX_DEVICE_NAME];
unsigned long long rd_sectors;
unsigned long long wr_sectors;
unsigned long rd_ops;
unsigned long wr_ops;
};
/* 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_list; /* List of devices entered on the command line */
struct stats_dev *saved_stats_dev;
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[16];
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[20];
/* %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], *ibuf = buf + 4;
fp = xfopen_for_read("/proc/stat");
memset(sc, 0, sizeof(*sc));
while (fgets(buf, sizeof(buf), fp)) {
/* Does the line starts with "cpu "? */
if (!starts_with_cpu(buf) || buf[3] != ' ') {
continue;
}
for (int 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(" %6.2f %6.2f %6.2f %6.2f %6.2f %6.2f\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 print_stats_dev_struct(const struct stats_dev *p,
const struct stats_dev *c, cputime_t itv)
{
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", c->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 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_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 void do_disk_statistics(cputime_t itv)
{
FILE *fp;
int rc;
int i = 0;
char buf[128];
unsigned major, minor;
unsigned long wr_ops, dummy; /* %*lu for suppress the conversion wouldn't work */
unsigned long long rd_sec_or_wr_ops;
unsigned long long rd_sec_or_dummy, wr_sec_or_dummy, wr_sec;
struct stats_dev sd;
fp = xfopen_for_read("/proc/diskstats");
/* Read and possibly print stats from /proc/diskstats */
while (fgets(buf, sizeof(buf), fp)) {
rc = sscanf(buf, "%u %u %s %lu %llu %llu %llu %lu %lu %llu %lu %lu %lu %lu",
&major, &minor, sd.dname, &sd.rd_ops,
&rd_sec_or_dummy, &rd_sec_or_wr_ops, &wr_sec_or_dummy,
&wr_ops, &dummy, &wr_sec, &dummy, &dummy, &dummy, &dummy);
switch (rc) {
case 14:
sd.wr_ops = wr_ops;
sd.rd_sectors = rd_sec_or_wr_ops;
sd.wr_sectors = wr_sec;
break;
case 7:
sd.rd_sectors = rd_sec_or_dummy;
sd.wr_ops = (unsigned long)rd_sec_or_wr_ops;
sd.wr_sectors = wr_sec_or_dummy;
break;
default:
break;
}
if (!G.dev_list && !is_partition(sd.dname)) {
/* User didn't specify device */
if (!G.show_all && !sd.rd_ops && !sd.wr_ops) {
/* Don't print unused device */
continue;
}
print_stats_dev_struct(&G.saved_stats_dev[i], &sd, itv);
G.saved_stats_dev[i] = sd;
i++;
} else {
/* Is device in device list? */
if (llist_find_str(G.dev_list, sd.dname)) {
/* Print current statistics */
print_stats_dev_struct(&G.saved_stats_dev[i], &sd, itv);
G.saved_stats_dev[i] = sd;
i++;
} else
continue;
}
}
fclose(fp);
}
static void dev_report(cputime_t itv)
{
/* Always print a header */
print_devstat_header();
/* Fetch current disk statistics */
do_disk_statistics(itv);
}
static unsigned get_number_of_devices(void)
{
FILE *fp;
char buf[128];
int rv;
unsigned n = 0;
unsigned long rd_ops, wr_ops;
char dname[MAX_DEVICE_NAME];
fp = xfopen_for_read("/proc/diskstats");
while (fgets(buf, sizeof(buf), fp)) {
rv = sscanf(buf, "%*d %*d %s %lu %*u %*u %*u %lu",
dname, &rd_ops, &wr_ops);
if (rv == 2 || is_partition(dname))
/* A partition */
continue;
if (!rd_ops && !wr_ops) {
/* Unused device */
if (!G.show_all)
continue;
}
n++;
}
fclose(fp);
return n;
}
//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: "\nOptions:"
//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, dev_num;
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 */
dev_num = 0;
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_list, dev_name)) {
llist_add_to(&G.dev_list, dev_name);
dev_num++;
}
} 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);
}
/* Allocate space for device stats */
if (opt & OPT_d) {
G.saved_stats_dev = xzalloc(sizeof(G.saved_stats_dev[0]) *
(dev_num ? dev_num : get_number_of_devices())
);
}
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_list, NULL);
free(G.saved_stats_dev);
free(&G);
}
return EXIT_SUCCESS;
}