1 /* vmstat.c - Report virtual memory statistics.
2 *
3 * Copyright 2012 Elie De Brauwer <[email protected]>
4 *
5 * TODO: I have no idea how "system" category is calculated.
6 * whatever we're doing isn't matching what other implementations are doing.
7
8 USE_VMSTAT(NEWTOY(vmstat, ">2n", TOYFLAG_BIN|TOYFLAG_LINEBUF))
9
10 config VMSTAT
11 bool "vmstat"
12 default y
13 help
14 usage: vmstat [-n] [DELAY [COUNT]]
15
16 Print virtual memory statistics, repeating each DELAY seconds, COUNT times.
17 (With no DELAY, prints one line. With no COUNT, repeats until killed.)
18
19 Show processes running and blocked, kilobytes swapped, free, buffered, and
20 cached, kilobytes swapped in and out per second, file disk blocks input and
21 output per second, interrupts and context switches per second, percent
22 of CPU time spent running user code, system code, idle, and awaiting I/O.
23 First line is since system started, later lines are since last line.
24
25 -n Display the header only once
26 */
27
28 #define FOR_vmstat
29 #include "toys.h"
30
31 struct vmstat_proc {
32 unsigned long long
33 // From /proc/stat (jiffies) 0-10
34 user, nice, sys, idle, wait, irq, sirq, intr, ctxt, running, blocked,
35 // From /proc/meminfo (units are kb) 11-16
36 memfree, buffers, cached, swapfree, swaptotal, reclaimable,
37 // From /proc/vmstat (units are kb) 17-18
38 io_in, io_out,
39 // From /proc/vmstat (units are pages) 19-20
40 swap_in, swap_out;
41 };
42
43 // All the elements of vmstat_proc are the same size, so we can populate it as
44 // a big array, then read the elements back out by name
get_vmstat_proc(struct vmstat_proc * vmsp)45 static void get_vmstat_proc(struct vmstat_proc *vmsp)
46 {
47 char *vmstuff[] = { "/proc/stat", "cpu ", 0, 0, 0, 0, 0, 0, "intr ", "ctxt ",
48 "procs_running ", "procs_blocked ", "/proc/meminfo", "MemFree:",
49 "Buffers:", "Cached:", "SwapFree:", "SwapTotal:", "SReclaimable:",
50 "/proc/vmstat", "pgpgin ", "pgpgout ", "pswpin ", "pswpout " };
51 unsigned long long *new = (void *)vmsp;
52 char *p = 0, *name = name, *file = 0;
53 int i, j;
54
55 // We use vmstuff to fill out vmstat_proc as an array of long long:
56 // Strings starting with / are the file to find next entries in
57 // Any other string is a key to search for, with decimal value right after
58 // 0 means parse another value on same line as last key
59
60 memset(new, 0, sizeof(struct vmstat_proc));
61 for (i = j = 0; i<ARRAY_LEN(vmstuff); i++) {
62 if (!vmstuff[i]) p++; // Read next entry on same line
63 else if (*vmstuff[i] == '/') {
64 free(file);
65 file = xreadfile(name = vmstuff[i], 0, 0);
66
67 continue;
68 } else if (file && !(p = strafter(file, vmstuff[i]))) {
69 free(file);
70 file = 0;
71 }
72 if (!file) new++;
73 else if (1==sscanf(p, "%llu%n", new++, &j)) p += j;
74 }
75 free(file);
76
77 // combine some fields we display as aggregates
78 vmsp->running--; // Don't include ourselves
79 vmsp->user += vmsp->nice;
80 vmsp->sys += vmsp->irq + vmsp->sirq;
81 vmsp->swaptotal -= vmsp->swapfree;
82 vmsp->cached += vmsp->reclaimable;
83 }
84
vmstat_main(void)85 void vmstat_main(void)
86 {
87 int i, loop_delay = 0, loop_max = 0;
88 unsigned loop, rows = 25, page_kb = sysconf(_SC_PAGESIZE)/1024;
89 unsigned long long units, total_hz, *ptr, *oldptr;
90 char *headers = "r\0b\0swpd\0free\0buff\0cache\0si\0so\0bi\0bo\0in\0cs\0us\0"
91 "sy\0id\0wa", lengths[] = {2,2,7,7,6,7,4,4,5,5,4,4,2,2,2,2};
92
93 if (toys.optc) loop_delay = atolx_range(toys.optargs[0], 0, INT_MAX);
94 if (toys.optc>1) loop_max = atolx_range(toys.optargs[1], 1, INT_MAX);
95
96 xreadfile("/proc/uptime", toybuf, sizeof(toybuf));
97 sscanf(toybuf, "%*s %llu", &units);
98
99 for (loop = 0; !loop_max || loop<loop_max; loop++) {
100 unsigned offset = 0, expected = 0;
101
102 if (loop && loop_delay) sleep(loop_delay);
103
104 ptr = oldptr = (void *)toybuf;
105 *((loop&1) ? &ptr : &oldptr) += sizeof(struct vmstat_proc);
106 get_vmstat_proc((void *)ptr);
107
108 // Print headers
109 if (rows>3 && !(loop % (rows-3))) {
110 char *header = headers;
111
112 if (!FLAG(n) && isatty(1)) terminal_size(0, &rows);
113 else rows = 0;
114
115 printf("procs ------------memory------------ ---swap-- -----io---- --system- ----cpu----\n");
116 for (i = 0; i<sizeof(lengths); i++) {
117 printf(" %*s"+!i, lengths[i], header);
118 header += strlen(header)+1;
119 }
120 xputc('\n');
121 }
122
123 if (loop) units = loop_delay;
124
125 // add up user, sys, idle, and wait time used since last time
126 // (Already appended nice to user)
127 for (i = total_hz = 0; i<4; i++) total_hz += ptr[i+!!i] - oldptr[i+!!i];
128
129 // Output values in order[]: running, blocked, swaptotal, memfree, buffers,
130 // cache, swap_in, swap_out, io_in, io_out, intr, ctxt, user, sys, idle,wait
131
132 for (i=0; i<sizeof(lengths); i++) {
133 char order[] = {9, 10, 15, 11, 12, 13, 19, 20, 17, 18, 7, 8, 0, 2, 3, 4};
134 unsigned long long out = ptr[order[i]];
135 int len;
136
137 // Adjust rate and units
138 if (i>5) out -= oldptr[order[i]];
139 if (order[i]<7) out = ((out*100) + (total_hz/2)) / total_hz;
140 else if (order[i]>16) {
141 if (order[i]>18) out *= page_kb;
142 out = (out*page_kb+(units-1))/units;
143 } else if (order[i]<9) out = (out+(units-1)) / units;
144
145 // If a field was too big to fit in its slot, try to compensate later
146 expected += lengths[i] + !!i;
147 len = expected - offset - !!i;
148 if (len < 0) len = 0;
149 offset += printf(" %*llu"+!i, len, out);
150 }
151 xputc('\n');
152
153 if (!loop_delay) break;
154 }
155 }
156