1/* vmstat.c - Report virtual memory statistics.
2 *
3 * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
4
5USE_VMSTAT(NEWTOY(vmstat, ">2n", TOYFLAG_BIN))
6
7config VMSTAT
8  bool "vmstat"
9  default y
10  help
11    usage: vmstat [-n] [DELAY [COUNT]]
12
13    Print virtual memory statistics, repeating each DELAY seconds, COUNT times.
14    (With no DELAY, prints one line. With no COUNT, repeats until killed.)
15
16    Show processes running and blocked, kilobytes swapped, free, buffered, and
17    cached, kilobytes swapped in and out per second, file disk blocks input and
18    output per second, interrupts and context switches per second, percent
19    of CPU time spent running user code, system code, idle, and awaiting I/O.
20    First line is since system started, later lines are since last line.
21
22    -n	Display the header only once
23*/
24
25#define FOR_vmstat
26#include "toys.h"
27
28struct vmstat_proc {
29  // From /proc/stat (jiffies)
30  uint64_t user, nice, sys, idle, wait, irq, sirq, intr, ctxt, running, blocked;
31  // From /proc/meminfo (units are kb)
32  uint64_t memfree, buffers, cached, swapfree, swaptotal;
33  // From /proc/vmstat (units are pages)
34  uint64_t io_in, io_out, swap_in, swap_out;
35};
36
37// All the elements of vmstat_proc are the same size, so we can populate it as
38// a big array, then read the elements back out by name
39void get_vmstat_proc(struct vmstat_proc *vmstat_proc)
40{
41  char *vmstuff[] = { "/proc/stat", "cpu ", 0, 0, 0, 0, 0, 0,
42    "intr ", "ctxt ", "procs_running ", "procs_blocked ", "/proc/meminfo",
43    "MemFree: ", "Buffers: ", "Cached: ", "SwapFree: ", "SwapTotal: ",
44    "/proc/vmstat", "pgpgin ", "pgpgout ", "pswpin ", "pswpout " };
45  uint64_t *new = (uint64_t *)vmstat_proc;
46  char *p = p, *name = name;
47  int i, j;
48
49  // We use vmstuff to fill out vmstat_proc as an array of uint64_t:
50  //   Strings starting with / are the file to find next entries in
51  //   Any other string is a key to search for, with decimal value right after
52  //   0 means parse another value on same line as last key
53
54  for (i = 0; i<sizeof(vmstuff)/sizeof(char *); i++) {
55    if (!vmstuff[i]) p++;
56    else if (*vmstuff[i] == '/') {
57      xreadfile(name = vmstuff[i], toybuf, sizeof(toybuf));
58
59      continue;
60    } else {
61      if (!(p = strstr(toybuf, vmstuff[i]))) goto error;
62      p += strlen(vmstuff[i]);
63    }
64    if (1 != sscanf(p, "%"PRIu64"%n", new++, &j)) goto error;
65    p += j;
66  }
67
68  return;
69
70error:
71  error_exit("No %sin %s\n", vmstuff[i], name);
72}
73
74void vmstat_main(void)
75{
76  struct vmstat_proc top[2];
77  int i, loop_delay = 0, loop_max = 0;
78  unsigned loop, rows = (toys.optflags & FLAG_n) ? 0 : 25,
79           page_kb = sysconf(_SC_PAGESIZE)/1024;
80  char *headers="r\0b\0swpd\0free\0buff\0cache\0si\0so\0bi\0bo\0in\0cs\0us\0"
81                "sy\0id\0wa", lengths[] = {2,2,6,6,6,6,4,4,5,5,4,4,2,2,2,2};
82
83  memset(top, 0, sizeof(top));
84  if (toys.optc) loop_delay = atolx_range(toys.optargs[0], 0, INT_MAX);
85  if (toys.optc > 1) loop_max = atolx_range(toys.optargs[1], 1, INT_MAX) - 1;
86
87  for (loop = 0; !loop_max || loop <= loop_max; loop++) {
88    unsigned idx = loop&1, offset = 0, expected = 0;
89    uint64_t units, total_hz, *ptr = (uint64_t *)(top+idx),
90             *oldptr = (uint64_t *)(top+!idx);
91
92    if (loop && loop_delay) sleep(loop_delay);
93
94    // Print headers
95    if (rows>3 && !(loop % (rows-3))) {
96      if (isatty(1)) terminal_size(0, &rows);
97      else rows = 0;
98
99      printf("procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----\n");
100
101      for (i=0; i<sizeof(lengths); i++) {
102        printf(" %*s"+!i, lengths[i], headers);
103        headers += strlen(headers)+1;
104      }
105      xputc('\n');
106    }
107
108    // Read data and combine some fields we display as aggregates
109    get_vmstat_proc(top+idx);
110    top[idx].running--; // Don't include ourselves
111    top[idx].user += top[idx].nice;
112    top[idx].sys += top[idx].irq + top[idx].sirq;
113    top[idx].swaptotal -= top[idx].swapfree;
114
115    // Collect unit adjustments (outside the inner loop to save time)
116
117    if (!loop) {
118      char *s = toybuf;
119
120      xreadfile("/proc/uptime", toybuf, sizeof(toybuf)-1);
121      while (*(s++) > ' ');
122      sscanf(s, "%"PRIu64, &units);
123    } else units = loop_delay;
124
125    // add up user, sys, idle, and wait time used since last time
126    // (Already appended nice to user)
127    total_hz = 0;
128    for (i=0; i<4; i++) total_hz += ptr[i+!!i] - oldptr[i+!!i];
129
130    // Output values in order[]: running, blocked, swaptotal, memfree, buffers,
131    // cache, swap_in, swap_out, io_in, io_out, sirq, ctxt, user, sys, idle,wait
132
133    for (i=0; i<sizeof(lengths); i++) {
134      char order[] = {9, 10, 15, 11, 12, 13, 18, 19, 16, 17, 6, 8, 0, 2, 3, 4};
135      uint64_t out = ptr[order[i]];
136      int len;
137
138      // Adjust rate and units
139      if (i>5) out -= oldptr[order[i]];
140      if (order[i]<7) out = ((out*100) + (total_hz/2)) / total_hz;
141      else if (order[i]>15) out = ((out * page_kb)+(units-1))/units;
142      else if (order[i]<9) out = (out+(units-1)) / units;
143
144      // If a field was too big to fit in its slot, try to compensate later
145      expected += lengths[i] + !!i;
146      len = expected - offset - !!i;
147      if (len < 0) len = 0;
148      offset += printf(" %*"PRIu64+!i, len, out);
149    }
150    xputc('\n');
151
152    if (!loop_delay) break;
153  }
154}
155