wmmemload/src/mem_freebsd.c

   1 /*
   2  * mem_freebsd.c - module to get memory/swap usages in percent, for FreeBSD
   3  *
   4  * Copyright(c) 2001 Seiichi SATO <ssato@sh.rim.or.jp>
   5  *
   6  * licensed under the GPL
   7  */
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include "config.h"
  11 #endif
  12
  13 #include <stdio.h>
  14 #include <unistd.h>
  15 #include <stdlib.h>
  16 #include "mem.h"
  17
  18 #include <kvm.h>
  19 #include <fcntl.h>
  20 #include <sys/vmmeter.h>
  21 #include <time.h>
  22
  23 static kvm_t *kvm_data = NULL;
  24 static int pageshift;
  25 static struct nlist nlst[] = { {"_cp_time"}, {"_cnt"}, {0} };
  26
  27 /* initialize function */
  28 void mem_init(void)
  29 {
  30     int pagesize = getpagesize();
  31     pageshift = 0;
  32
  33     while (pagesize > 1) {
  34         pageshift++;
  35         pagesize >>= 1;
  36     }
  37
  38     kvm_data = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open");
  39
  40     if (kvm_data == NULL) {
  41         fprintf(stderr, "can't open kernel virtual memory");
  42         exit(1);
  43     }
  44     kvm_nlist(kvm_data, nlst);
  45
  46     if (nlst[0].n_type == 0 || nlst[1].n_type == 0) {
  47         fprintf(stderr, "error extracting symbols");
  48         exit(1);
  49     }
  50     /* drop setgid & setuid (the latter should not be there really) */
  51     seteuid(getuid());
  52     setegid(getgid());
  53
  54     if (geteuid() != getuid() || getegid() != getgid()) {
  55         fprintf(stderr, "unable to drop privileges");
  56         exit(1);
  57     }
  58 }
  59
  60
  61 /* return mem/swap usage in percent 0 to 100 */
  62 void mem_getusage(int *per_mem, int *per_swap, const struct mem_options *opts)
  63 {
  64     struct vmmeter vm;
  65     int bufspace;
  66     static int swap_firsttime = 1;
  67     static int swappgsin = -1;
  68     static int swappgsout = -1;
  69     static int swapmax = 0, swapused = 0;
  70     time_t cur_time;
  71     static time_t last_time_swap = 0;
  72     u_int mused;
  73
  74     /* get mem usage */
  75     if (kvm_read(kvm_data, nlst[0].n_value, &bufspace, sizeof(bufspace)) !=
  76         sizeof(bufspace))
  77         exit(1);
  78     if (kvm_read(kvm_data, nlst[1].n_value, &vm, sizeof(vm)) != sizeof(vm))
  79         exit(1);
  80
  81     /* get swap usage */
  82     /* only calculate when first time or when changes took place         */
  83     /* do not call it more than 1 time per 2 seconds                     */
  84     /* otherwise it can eat up to 50% of CPU time on heavy swap activity */
  85     cur_time = time(NULL);
  86     if (swap_firsttime ||
  87         (((vm.v_swappgsin > swappgsin) || (vm.v_swappgsout > swappgsout))
  88          && cur_time > last_time_swap + 1)) {
  89
  90         struct kvm_swap swap;
  91         int n;
  92
  93         swapmax = 0;
  94         swapused = 0;
  95
  96         n = kvm_getswapinfo(kvm_data, &swap, 1, 0);
  97         if (n >= 0 && swap.ksw_total != 0) {
  98             swapmax = swap.ksw_total;
  99             swapused = swap.ksw_used;
 100         }
 101
 102         swap_firsttime = 0;
 103         last_time_swap = cur_time;
 104     }
 105     swappgsin = vm.v_swappgsin;
 106     swappgsout = vm.v_swappgsout;
 107
 108 #ifdef DEBUG
 109     printf ("-------------------\n");
 110     printf ("total:%10d\n", vm.v_page_count * vm.v_page_size);
 111     printf ("free :%10d\n", vm.v_free_count * vm.v_page_size);
 112     printf ("act  :%10d\n", vm.v_active_count * vm.v_page_size);
 113     printf ("inact:%10d\n", vm.v_inactive_count * vm.v_page_size);
 114     printf ("wired:%10d\n", vm.v_wire_count * vm.v_page_size);
 115     printf ("cache:%10d\n", vm.v_cache_count * vm.v_page_size);
 116     printf ("-------------------\n");
 117 #endif
 118
 119     /* calc mem/swap usage in percent */
 120     mused = vm.v_page_count - vm.v_free_count;
 121     if (opts->ignore_wired) mused -= vm.v_wire_count;
 122     if (opts->ignore_cached) mused -= vm.v_cache_count;
 123
 124     *per_mem = 100 * (double) mused / (double) vm.v_page_count;
 125     *per_swap = 100 * (double) swapused / (double) swapmax;
 126
 127     if (*per_mem > 97) *per_mem = 100;
 128 }