1 /* vmstat.c - Report virtual memory statistics.
2 *
3 * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
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))
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 // From /proc/stat (jiffies)
33 uint64_t user, nice, sys, idle, wait, irq, sirq, intr, ctxt, running, blocked;
34 // From /proc/meminfo (units are kb)
35 uint64_t memfree, buffers, cached, swapfree, swaptotal;
36 // From /proc/vmstat (units are kb)
37 uint64_t io_in, io_out;
38 // From /proc/vmstat (units are pages)
39 uint64_t swap_in, swap_out;
40 };
41
42 // All the elements of vmstat_proc are the same size, so we can populate it as
43 // a big array, then read the elements back out by name
get_vmstat_proc(struct vmstat_proc * vmstat_proc)44 static void get_vmstat_proc(struct vmstat_proc *vmstat_proc)
45 {
46 char *vmstuff[] = { "/proc/stat", "cpu ", 0, 0, 0, 0, 0, 0,
47 "intr ", "ctxt ", "procs_running ", "procs_blocked ", "/proc/meminfo",
48 "MemFree: ", "Buffers: ", "Cached: ", "SwapFree: ", "SwapTotal: ",
49 "/proc/vmstat", "pgpgin ", "pgpgout ", "pswpin ", "pswpout " };
50 uint64_t *new = (uint64_t *)vmstat_proc;
51 char *p = p, *name = name, *file = NULL;
52 int i, j;
53
54 // We use vmstuff to fill out vmstat_proc as an array of uint64_t:
55 // Strings starting with / are the file to find next entries in
56 // Any other string is a key to search for, with decimal value right after
57 // 0 means parse another value on same line as last key
58
59 for (i = 0; i<ARRAY_LEN(vmstuff); i++) {
60 if (!vmstuff[i]) p++;
61 else if (*vmstuff[i] == '/') {
62 // /proc/stat for a 48-core machine doesn't fit in toybuf.
63 free(file);
64 file = xreadfile(name = vmstuff[i], 0, 0);
65
66 continue;
67 } else p = strafter(file, vmstuff[i]);
68 if (!p || 1!=sscanf(p, "%"PRIu64"%n", new++, &j))
69 error_exit("Bad %sin %s: %s", vmstuff[i], name, p ? p : "");
70 p += j;
71 }
72 free(file);
73 }
74
vmstat_main(void)75 void vmstat_main(void)
76 {
77 struct vmstat_proc top[2];
78 int i, loop_delay = 0, loop_max = 0;
79 unsigned loop, rows = 25, 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);
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 char *header = headers;
97
98 if (!(toys.optflags&FLAG_n) && isatty(1)) terminal_size(0, &rows);
99 else rows = 0;
100
101 printf("procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----\n");
102 for (i=0; i<sizeof(lengths); i++) {
103 printf(" %*s"+!i, lengths[i], header);
104 header += strlen(header)+1;
105 }
106 xputc('\n');
107 }
108
109 // Read data and combine some fields we display as aggregates
110 get_vmstat_proc(top+idx);
111 top[idx].running--; // Don't include ourselves
112 top[idx].user += top[idx].nice;
113 top[idx].sys += top[idx].irq + top[idx].sirq;
114 top[idx].swaptotal -= top[idx].swapfree;
115
116 // Collect unit adjustments (outside the inner loop to save time)
117
118 if (!loop) {
119 char *s = toybuf;
120
121 xreadfile("/proc/uptime", toybuf, sizeof(toybuf));
122 while (*(s++) > ' ');
123 sscanf(s, "%"PRIu64, &units);
124 } else units = loop_delay;
125
126 // add up user, sys, idle, and wait time used since last time
127 // (Already appended nice to user)
128 total_hz = 0;
129 for (i=0; i<4; i++) total_hz += ptr[i+!!i] - oldptr[i+!!i];
130
131 // Output values in order[]: running, blocked, swaptotal, memfree, buffers,
132 // cache, swap_in, swap_out, io_in, io_out, sirq, ctxt, user, sys, idle,wait
133
134 for (i=0; i<sizeof(lengths); i++) {
135 char order[] = {9, 10, 15, 11, 12, 13, 18, 19, 16, 17, 6, 8, 0, 2, 3, 4};
136 uint64_t out = ptr[order[i]];
137 int len;
138
139 // Adjust rate and units
140 if (i>5) out -= oldptr[order[i]];
141 if (order[i]<7) out = ((out*100) + (total_hz/2)) / total_hz;
142 else if (order[i]>17) out = ((out * page_kb)+(units-1))/units;
143 else if (order[i]>15) out = ((out)+(units-1))/units;
144 else if (order[i]<9) out = (out+(units-1)) / units;
145
146 // If a field was too big to fit in its slot, try to compensate later
147 expected += lengths[i] + !!i;
148 len = expected - offset - !!i;
149 if (len < 0) len = 0;
150 offset += printf(" %*"PRIu64+!i, len, out);
151 }
152 xputc('\n');
153
154 if (!loop_delay) break;
155 }
156 }
157