1 /*
2 * linux/kernel/info.c
3 *
4 * Copyright (C) 1992 Darren Senn
5 */
6
7 /* This implements the sysinfo() system call */
8
9 #include <linux/mm.h>
10 #include <linux/unistd.h>
11 #include <linux/swap.h>
12 #include <linux/smp_lock.h>
13
14 #include <asm/uaccess.h>
15
sys_sysinfo(struct sysinfo * info)16 asmlinkage long sys_sysinfo(struct sysinfo *info)
17 {
18 struct sysinfo val;
19
20 memset((char *)&val, 0, sizeof(struct sysinfo));
21
22 cli();
23 val.uptime = jiffies / HZ;
24
25 val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);
26 val.loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);
27 val.loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
28
29 val.procs = nr_threads-1;
30 sti();
31
32 si_meminfo(&val);
33 si_swapinfo(&val);
34
35 {
36 unsigned long mem_total, sav_total;
37 unsigned int mem_unit, bitcount;
38
39 /* If the sum of all the available memory (i.e. ram + swap)
40 * is less than can be stored in a 32 bit unsigned long then
41 * we can be binary compatible with 2.2.x kernels. If not,
42 * well, in that case 2.2.x was broken anyways...
43 *
44 * -Erik Andersen <andersee@debian.org> */
45
46 mem_total = val.totalram + val.totalswap;
47 if (mem_total < val.totalram || mem_total < val.totalswap)
48 goto out;
49 bitcount = 0;
50 mem_unit = val.mem_unit;
51 while (mem_unit > 1) {
52 bitcount++;
53 mem_unit >>= 1;
54 sav_total = mem_total;
55 mem_total <<= 1;
56 if (mem_total < sav_total)
57 goto out;
58 }
59
60 /* If mem_total did not overflow, multiply all memory values by
61 * val.mem_unit and set it to 1. This leaves things compatible
62 * with 2.2.x, and also retains compatibility with earlier 2.4.x
63 * kernels... */
64
65 val.mem_unit = 1;
66 val.totalram <<= bitcount;
67 val.freeram <<= bitcount;
68 val.sharedram <<= bitcount;
69 val.bufferram <<= bitcount;
70 val.totalswap <<= bitcount;
71 val.freeswap <<= bitcount;
72 val.totalhigh <<= bitcount;
73 val.freehigh <<= bitcount;
74 }
75 out:
76 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
77 return -EFAULT;
78 return 0;
79 }
80