src/proc_interrupts.c

   1 #include "common.h"
   2
   3 #define MAX_INTERRUPT_NAME 50
   4
   5 struct interrupt {
   6         int used;
   7         char *id;
   8         char name[MAX_INTERRUPT_NAME + 1];
   9         unsigned long long total;
  10         unsigned long long value[];
  11 };
  12
  13 // since each interrupt is variable in size
  14 // we use this to calculate its record size
  15 #define recordsize(cpus) (sizeof(struct interrupt) + (cpus * sizeof(unsigned long long)))
  16
  17 // given a base, get a pointer to each record
  18 #define irrindex(base, line, cpus) ((struct interrupt *)&((char *)(base))[line * recordsize(cpus)])
  19
  20 static inline struct interrupt *get_interrupts_array(int lines, int cpus) {
  21         static struct interrupt *irrs = NULL;
  22         static int allocated = 0;
  23
  24         if(lines < allocated) return irrs;
  25         else {
  26                 irrs = (struct interrupt *)realloc(irrs, lines * recordsize(cpus));
  27                 if(!irrs)
  28                         fatal("Cannot allocate memory for %d interrupts", lines);
  29
  30                 allocated = lines;
  31         }
  32
  33         return irrs;
  34 }
  35
  36 int do_proc_interrupts(int update_every, unsigned long long dt) {
  37         static procfile *ff = NULL;
  38         static int cpus = -1, do_per_core = -1;
  39         struct interrupt *irrs = NULL;
  40
  41         if(dt) {};
  42
  43         if(do_per_core == -1) do_per_core = config_get_boolean("plugin:proc:/proc/interrupts", "interrupts per core", 1);
  44
  45         if(!ff) {
  46                 char filename[FILENAME_MAX + 1];
  47                 snprintfz(filename, FILENAME_MAX, "%s%s", global_host_prefix, "/proc/interrupts");
  48                 ff = procfile_open(config_get("plugin:proc:/proc/interrupts", "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
  49         }
  50         if(!ff) return 1;
  51
  52         ff = procfile_readall(ff);
  53         if(!ff) return 0; // we return 0, so that we will retry to open it next time
  54
  55         uint32_t lines = procfile_lines(ff), l;
  56         uint32_t words = procfile_linewords(ff, 0), w;
  57
  58         if(!lines) {
  59                 error("Cannot read /proc/interrupts, zero lines reported.");
  60                 return 1;
  61         }
  62
  63         // find how many CPUs are there
  64         if(cpus == -1) {
  65                 cpus = 0;
  66                 for(w = 0; w < words ; w++) {
  67                         if(strncmp(procfile_lineword(ff, 0, w), "CPU", 3) == 0)
  68                                 cpus++;
  69                 }
  70         }
  71
  72         if(!cpus) {
  73                 error("PLUGIN: PROC_INTERRUPTS: Cannot find the number of CPUs in /proc/interrupts");
  74                 return 1;
  75         }
  76
  77         // allocate the size we need;
  78         irrs = get_interrupts_array(lines, cpus);
  79         irrs[0].used = 0;
  80
  81         // loop through all lines
  82         for(l = 1; l < lines ;l++) {
  83                 struct interrupt *irr = irrindex(irrs, l, cpus);
  84                 irr->used = 0;
  85                 irr->total = 0;
  86
  87                 words = procfile_linewords(ff, l);
  88                 if(!words) continue;
  89
  90                 irr->id = procfile_lineword(ff, l, 0);
  91                 if(!irr->id || !irr->id[0]) continue;
  92
  93                 int idlen = strlen(irr->id);
  94                 if(irr->id[idlen - 1] == ':')
  95                         irr->id[idlen - 1] = '\0';
  96
  97                 int c;
  98                 for(c = 0; c < cpus ;c++) {
  99                         if((c + 1) < (int)words)
 100                                 irr->value[c] = strtoull(procfile_lineword(ff, l, (uint32_t)(c + 1)), NULL, 10);
 101                         else
 102                                 irr->value[c] = 0;
 103
 104                         irr->total += irr->value[c];
 105                 }
 106
 107                 if(isdigit(irr->id[0]) && (uint32_t)(cpus + 2) < words) {
 108                         strncpyz(irr->name, procfile_lineword(ff, l, words - 1), MAX_INTERRUPT_NAME);
 109                         int nlen = strlen(irr->name);
 110                         if(nlen < (MAX_INTERRUPT_NAME-1)) {
 111                                 irr->name[nlen] = '_';
 112                                 strncpyz(&irr->name[nlen + 1], irr->id, MAX_INTERRUPT_NAME - nlen);
 113                         }
 114                 }
 115                 else {
 116                         strncpyz(irr->name, irr->id, MAX_INTERRUPT_NAME);
 117                 }
 118
 119                 irr->used = 1;
 120         }
 121
 122         RRDSET *st;
 123
 124         // --------------------------------------------------------------------
 125
 126         st = rrdset_find_bytype("system", "interrupts");
 127         if(!st) {
 128                 st = rrdset_create("system", "interrupts", NULL, "interrupts", NULL, "System interrupts", "interrupts/s", 1000, update_every, RRDSET_TYPE_STACKED);
 129
 130                 for(l = 0; l < lines ;l++) {
 131                         struct interrupt *irr = irrindex(irrs, l, cpus);
 132                         if(!irr->used) continue;
 133                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 134                 }
 135         }
 136         else rrdset_next(st);
 137
 138         for(l = 0; l < lines ;l++) {
 139                 struct interrupt *irr = irrindex(irrs, l, cpus);
 140                 if(!irr->used) continue;
 141                 rrddim_set(st, irr->id, irr->total);
 142         }
 143         rrdset_done(st);
 144
 145         if(do_per_core) {
 146                 int c;
 147
 148                 for(c = 0; c < cpus ; c++) {
 149                         char id[256+1];
 150                         snprintfz(id, 256, "cpu%d_interrupts", c);
 151
 152                         st = rrdset_find_bytype("cpu", id);
 153                         if(!st) {
 154                                 char name[256+1], title[256+1];
 155                                 snprintfz(name, 256, "cpu%d_interrupts", c);
 156                                 snprintfz(title, 256, "CPU%d Interrupts", c);
 157                                 st = rrdset_create("cpu", id, name, "interrupts", "cpu.interrupts", title, "interrupts/s", 2000 + c, update_every, RRDSET_TYPE_STACKED);
 158
 159                                 for(l = 0; l < lines ;l++) {
 160                                         struct interrupt *irr = irrindex(irrs, l, cpus);
 161                                         if(!irr->used) continue;
 162                                         rrddim_add(st, irr->id, irr->name, 1, 1, RRDDIM_INCREMENTAL);
 163                                 }
 164                         }
 165                         else rrdset_next(st);
 166
 167                         for(l = 0; l < lines ;l++) {
 168                                 struct interrupt *irr = irrindex(irrs, l, cpus);
 169                                 if(!irr->used) continue;
 170                                 rrddim_set(st, irr->id, irr->value[c]);
 171                         }
 172                         rrdset_done(st);
 173                 }
 174         }
 175
 176         return 0;
 177 }