1 /* vmstat.c - Report virtual memory statistics.
2 *
3 * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
4
5 USE_VMSTAT(NEWTOY(vmstat, ">2n", TOYFLAG_BIN))
6
7 config 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
28 struct 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
get_vmstat_proc(struct vmstat_proc * vmstat_proc)39 void 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
70 error:
71 error_exit("No %sin %s\n", vmstuff[i], name);
72 }
73
vmstat_main(void)74 void 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